MeEnviro

Layanan Peta

noreply@blogger.com (Meenviro) — Thu, 10 Feb 2011 04:35:06 PST

Kami menyediakan berbagai peta dalam format file shp, jpg, bmp.
1. Peta geologi bersistem Indonesia
2. Peta land system pulau Kalimantan
3. Peta morfologi pulau Kalimantan
4. Peta Cekungan Air Tanah Indonesia
5. Peta Wilayah Sungai Indonesia
6. Peta Tutupan Lahan pulau Kalimantan
7. Peta Administrasi, jalan, pemukiman, sungai dll Indonesia
8. Peta litologi pulau Kalimantan
9. Peta batas KP dan PKP2B pulau Kalimantan
10. Peta kehutanan pulau Kalimantan
11. Peta potensi air tanah Indonesia
12. Peta lereng pulau kalimantan
13. Peta potensi sumber daya alam Indonesia
Harga mulai Rp. 50.000 tergantung lokasi dan luas wilayah.
Bila anda berminat silahkan kontak melalui facebook kami.

Climate change

noreply@blogger.com (Meenviro) — Tue, 28 Dec 2010 22:11:04 PST

Climate change is a long-term change in the statistical distribution of weather patterns over periods of time that range from decades to millions of years. It may be a change in the average weather conditions or a change in the distribution of weather events with respect to an average, for example, greater or fewer extreme weather events. Climate change may be limited to a specific region, or may occur across the whole Earth.

In recent usage, especially in the context of environmental policy, climate change usually refers to changes in modern climate. It may be qualified as anthropogenic climate change, more generally known as global warming or anthropogenic global warming (AGW).

Terminology

The most general definition of climate change is a change in the statistical properties of the climate system when considered over periods of decades or longer, regardless of cause.^[1]^[2] Accordingly, fluctuations on periods shorter than a few decades, such as El Ni�o, do not represent climate change.

The term sometimes is used to refer specifically to climate change caused by human activity; for example, the United Nations Framework Convention on Climate Change defines climate change as "a change of climate which is attributed directly or indirectly to human activity that alters the composition of the global atmosphere and which is in addition to natural climate variability observed over comparable time periods."^[3] In the latter sense climate change is synonymous with global warming.

Wastewater Treatment: Don't Forget the Paperwork

noreply@blogger.com (Meenviro) — Wed, 08 Dec 2010 08:15:01 PST

The process of developing, designing, and constructing an on-site wastewater system involves a considerable amount of paperwork. Fortunately, your wastewater design firm will help you with that aspect throughout the process and may even be willing to assist with unrelated official documentation. Here are a few of the related services your on-site wastewater management design firm may offer:

1. Wastewater Permit Acquisition

Whether state, local, municipal, or national, your Austin, Texas water management engineering firm can help you ascertain and attain the appropriate permits you may need from the various permit authorities such as the Texas Commission on Environmental Quality (TCEQ) and that you are in compliance with Texas Health and Safety codes. Because permit requirements differ based on property type and geographic location, having someone who fully understands the regulations as related to your area and field ensures things are properly done in a timely fashion so as not to cause any time delays or additional expenses.

2. Wastewater Permit Renewals

Your wastewater design firm should be able to assist in the regular renewal of permits they originally assisted with.

3. Bid Documents

During the preparatory phase for an on-site wastewater plant, the on-site sewage facility (OSSF) design company is able to assist with the preparation and administration of bid documents.

4. Public Bid Documents

If you are preparing a public bid for an OSSF, the treatment plan and all relative details need to be outlined and included in the bid document. An experienced OSSF design firm can ascertain and compile all the relative specifications to create a comprehensive bid document which accurately reflects your project.

5. Inspections

Before an on-site wastewater treatment option can be designed or built, a land feasibility study must be conducted. The geographical location will be inspected and evaluated based on the regulations that apply to the area. Your Texas wastewater design company can provide these preliminary inspections.

6. Site Design & Development

In the site design and development phase of the wastewater management process, the wastewater management team develops the plan for the proposed site and establishes that the site is suitable for wastewater effluent.

For all your Austin, Texas wastewater permitting needs, consult with WWD Engineering. WWD Engineering has been designing on-site sewage plants for properties across Texas since 1983; let them address your wastewater documentation requirements.

What You Need To Know About Wastewater

noreply@blogger.com (Meenviro) — Tue, 07 Dec 2010 17:13:55 PST

In the U.S., each person uses between 75 and 100 gallons of water on a daily basis. The resulting wastewater requires proper treatment and disposal. Considering its universal nature, it's remarkable how little most people know about wastewater. Here are some basics in order to better understand the private and public water we use every day.

What Is Wastewater?
Wastewater is essentially defined as used water. It comes from any property with people, on-site, using water such as offices, schools, residences, and restaurants, etc. as well from rain runoff. Often it includes food, human waste, grease, oil, chemicals, sand, and anything else put into the water before its disposal. In the typical home, wastewater originates in sinks, toilets, showers, dishwashers, and washing machines. It makes its way through the sewage system and into the off-site Austin wastewater purification facility where it will be thoroughly treated.

Why Treat Wastewater?
Waste water purification technology exists to ensure that chemicals and pollutants are largely removed to protect human and environmental health.

How to Treat Wastewater?
Wastewater goes through a variety of treatment processes, depending on the property, the related regulations, and the type of wastewater management system. If a property is located outside of city limits, it generally requires an OSSF for wastewater purification. Approximately 27% of the U.S. uses on-site wastewater management. An on-site water and wastewater management firm in Austin, Texas can help you determine if you need an on-site sewage treatment plant and which water treatments are needed for your type of wastewater. The plant may include preliminary, primary, secondary, tertiary, and final treatments to ensure your property's wastewater is properly treated.

If you need on-site sewage plant construction to handle drinking water to hazardous waste, consult with Wastewater Solutions of Austin, Texas. Wastewater Solutions offers quality construction, repair, and operation for on-site wastewater management in Central Texas and the surrounding areas, including San Marcos, Round Rock, and Georgetown.

Climate and the Carboniferous Period

noreply@blogger.com (Meenviro) — Sun, 05 Dec 2010 04:25:00 PST

West Virginia today is mostly an erosional plateau carved up into steep ridges and narrow valleys, but 300 million years ago, during the Carboniferous Period, it was part of a vast equatorial coastal swamp extending many hundreds of miles and barely rising above sea level. This steamy, tropical quagmire served as the nursery for Earth's first primitive forests, comprised of giant lycopods, ferns, and seed ferns.

North America was located along Earth's equator then, courtesy of the forces of continental drift. The hot and humid climate of the Middle Carboniferous Period was accompanied by an explosion of terrestrial plant life.

However by the Late Carboniferous Period Earth's climate had become increasingly cooler and drier. By the beginning of the Permian Period average global temperatures declined by about 10� C.

Interestingly, the last half of the Carboniferous Period witnessed periods of significant ice cap formation over polar landmasses-- particularly in the southern hemisphere. Alternating cool and warm periods during the ensuing Carboniferous Ice Age coincided with cycles of glacier expansion and retreat. Coastlines fluctuated, caused by a combination of both local basin subsidence and worldwide sea level changes. In West Virginia a complex system of meandering river deltas supported vast coal swamps that left repeating stratigraphic levels of peat bogs that later became coal, separated by layers of fluvial rocks like sandstone and shale when the deltas were building, and marine rocks like black shales and limestones when rising seas drowned coastlands.

Accumulations of several thousand feet of these sediments over millions of years caused heat and pressure which transformed the soft sediments into rock and the peat layers into the 100 or so coal seams which today comprise the Great Bituminous Coalfields of the Eastern U.S. and Western Europe (http://geology.about.com).

Earth's climate and atmosphere have varied greatly over geologic time. Our planet has mostly been much hotter and more humid than we know it to be today, and with far more carbon dioxide (the greenhouse gas) in the atmosphere than exists today

. The notable exception is 300,000,000 years ago during the late Carboniferous Period, which resembles our own climate and atmosphere like no other.

With this in mind the road to understanding global warming and our present climate begins with an historical journey through a chapter in Earth's history, some 30 million years before dinosaurs appeared, known as the Carboniferous Period-- a time when terrestrial Earth was ruled by giant plants and insects, and glaciers waxed and waned over a huge southern continent.

How Ozone Pollution Works

noreply@blogger.com (Meenviro) — Wed, 01 Dec 2010 04:19:00 PST

The weather report on the radio or TV tells you that it is going to be sunny and hot and that an orange ozone alert has been issued. What is ozone? What does an orange alert mean? Why should you be concerned about it?
In this article, we will examine what ozone is, how it is produced, what health hazards it poses and what you can do to reduce ozone pollution.

��Ozone is a molecule of three oxygen atoms bound together (O3). It is unstable and highly reactive. Ozone is used as a bleach, a deodorizing agent, and a sterilization agent for air and drinking water. At low concentrations, it is toxic.

Ozone is found naturally in small concentrations in the stratosphere, a layer of Earth's upper atmosphere. In this upper atmosphere, ozone is made when ultraviolet light from the sun splits an oxygen molecule (O2), forming two single oxygen atoms. If a freed atom collides with an oxogen molecule, it becomes ozone. Stratospheric ozone has been called "good" ozone because it protects the Earth's surface from dangerous ultraviolet light.

Ozone can also be found in the troposphere, the lowest layer of the atmosphere. Tropospheric ozone (often termed "bad" ozone) is man-made, a result of air pollution from internal combustion engines and power plants. Automobile exhaust and industrial emissions release a family of nitrogen oxide gases (NOx) and volatile organic compounds (VOC), by-products of burning gasoline and coal. NOx and VOC combine chemically with oxygen to form ozone during sunny, high-temperature conditions of late spring, summer and early fall. High levels of ozone are usually formed in the heat of the afternoon and early evening, dissipating during the cooler nights.

Although ozone pollution is formed mainly in urban and suburban areas, it ends up in rural areas as well, carried by prevailing winds or resulting from cars and trucks that travel into rural areas. Significant levels of ozone pollution can be detected in rural areas as far as 250 miles (402 kilometers) downwind from urban industrial zones.(http://science.howstuffworks.com)

Coal Prospects Bright Future

noreply@blogger.com (Meenviro) — Sat, 27 Nov 2010 04:16:00 PST

Demand for coal in the future are likely to experience substantial increases. At least it can be estimated that the demand of coal imports from some developed countries and developing countries. Based on data released by Merrill Lynch last June 8, 2010 the import requirement of coal in 2009 reached 591 metric tons (Mt), the year 2010 is estimated to increase to 635 Mt in 2015 and is expected to increase to 803 Mt.

Meanwhile, if it can estimated of coal consumption rate, according to the International Energy Agency (IEA) in 1990 total world coal consumption reached 3461 million tons, in 2007 increased to 5522 million tonnes, an increase of 59.5%, or an average of 3.5 % per annum. The IEA also estimates that world coal consumption will grow an average 2.6% per year between the period 2005 to 2015 and then slowed to an average of 1.7% per year during 2015-2030.
The increase in world coal consumption is inseparable from the rapidly increasing energy demand world where coal is the second biggest energy supplier after the oil with a contribution of 26%. This role is expected to rise to 29% in 2030. While its contribution as a power plant is also expected to increase from 41% in 2006 to 46% in 2030. The increasing role of coal as an energy supplier in the future to make this industry has a huge attraction for investors in Indonesia is no exception.

World Energy Council estimates that the world's proven coal reserves to reach 847,488 million tons by the end of 2007, which spread over more than 50 countries. Based on the calorie content, amounting to 50.8% in the form of anthracite (very high calorie) and bituminous (high calories), and 48.2% of sub-bituminous coal (medium calories) and lignite (low calorie). The IEA estimates that, with the current level of world coal production can be exploited at least until the next 133 years, longer than the proven oil and gas reserves are estimated to only be exploited about 42 and 60 years ahead.

Though spread over more than 50 countries, about 76.3% of proven coal reserves are concentrated in 5 countries namely the United States (28.6%), Russia (18.5%), China (13.5%), Australia (9% ) and India (6.7%). In 2007 these five countries accounted for 82% of total world coal production amounted to 5543 million tonnes.

Recorded the world's largest coal producer China, USA, India, Australia, South Africa and Indonesia. In 2007, the seven countries of this manufacturer produces about 90.6% of total world coal production. China is the largest producer which accounts for nearly half of world production that is 46% in 2007, followed by U.S. 17.7%, and India 8.2%. Although the largest coal producer, China as well recorded as the largest coal-consuming world that reached 46% of total world consumption. That is why the ranks of coal importing countries, China included the world's sixth largest importer with total imports of 48 million tons in 2007.

Prospect

Prospects for the future of coal estimated to be more bright. Despite the lowering demand for coal from OECD member countries, this decline will closed by increased demand in Asia, particularly China. Meanwhile, the existence of supply constraints, it would push up coal prices rise. It is estimated that coal prices will be in 2011 through US $ 110 / ton.
Issues relating to restrictions on coal exports from South Africa and is likely to relaxation in 2011 is expected to have an impact on price developments in the medium term. Similarly, Australia's coal exports are also expected to increase in 2011, however, can not be expected that high growth rate. Indonesia's export growth is predicted to experience slowdown, as more directed to meet domestic demand. In the last five years, Indonesia's exports increased by 80%, but in the next five years will probably go down just be 20%.
Despite a slowdown in demand growth, China's imports is expected to experience bullish. In the short term by China's coal demand is expected to be a change from moderate to very high levels. However, coal price is expected to be affected by seasonal factors, low inventory, and transportation problems. Meanwhile, in the long term, coal demand is expected to strengthen in line with the operation of coal fired power plants in Indonesia and China. Thus will remain a source of supply of interest to Indonesia and China.
Prospects seem bright coal will also be supported by the coal supply issues and strong demand growth from China and India.In South Africa will probably not face the problem of supply, however, this country may face further downside risk. This is due to the European coal market, the main buyer of South Africa, a bit having the pressure of Greece during a crisis.

However, South African exports will be back to normal, because in general, demand for coal from South African coal remains supported by lower freight rates and increased trade competitive position face to face the Asian market.

Meanwhile, Australia's coal exports in the next few years expected to increase in line with the operation of Newcastle at full capacity. Besides the increase in exports was also driven by increased production from the first stage NCIG and Kooragang Island coal terminal expansion. Meanwhile, in the coming years Australia will also get an additional supply due to start operation of Moolarben (6.2mtpa in 2011) and Narrabri (5mtpa in 2013).

The role of Indonesian
Indonesia itself has grown quite spectacular coal consumption within ten years. Increasing the amount of consumption of a very sharp increase was due to the sharp demand for coal as an energy source, especially for power generation, both domestically and in importing countries. Not surprising that along with the number of coal mining companies in Indonesia has grown rapidly especially in recent years. Until 2003 for example, recorded 251 coal mining company in Indonesia.

In line with the expected outlook for the coal business is getting better at the top, Indonesian coal exports is expected to remain will continue to grow, albeit with a lower growth rate than in previous years. In the last five years, Indonesia's coal exports rose from 129 Mt 92 005) to 220 Mt (2009), but in the next five years is estimated to Indonesia's export growth will experience a slowdown. In the year 2010 is estimated Indonesia's coal exports will reach 230 Mt in 2015 and increased to 276 Mt.

Indonesian coal exports in the future likely will be dominated by quality or low-calorie coal, which is coal that has high humidity and low energy content. However, Indonesia will be faced with the problem of higher shipping costs. The dominance of low-quality coal can not be separated from China and India as major coal markets of Indonesia, which does require a low-quality coal for new power plant them. Surely this is assuming the construction of power plants in both countries were not susceptible to interference.

In the arena of world coal trade, Indonesia will have an increasingly important role over the years either as producer or exporter. In 2009 Indonesia was in seventh position with the world's largest coal producer, contributing 4.2% and in the second position as the largest coal exporter with a total export volume of 220 Mt.

Volcanic Hazards

noreply@blogger.com (Meenviro) — Mon, 22 Nov 2010 13:16:32 PST

Volcanoes can be exciting and fascinating, but also very dangerous. Any kind of volcano is capable of creating harmful or deadly phenomena, whether during an eruption or a period of quiescence. Understanding what a volcano can do is the first step in mitigating volcanic hazards, but it is important to remember that even if scientists have studied a volcano for decades, they do not necessarily know everything it is capable of. Volcanoes are natural systems, and always have some element of unpredictability.

Volcanologists are always working to understand how volcanic hazards behave, and what can be done to avoid them. Here are a few of the more common hazards, and some of the ways that they are formed and behave. (Please note that this is intended as a source of basic information only, and should not be treated as a survival guide by those who live near a volcano. Always listen to the warnings and information issued by your local volcanologists and civil authorities.)

Lava Flows

Lava is molten rock that flows out of a volcano or volcanic vent. Depending on its composition and temperature, lava can be very fluid or very sticky (viscous). Fluid flows are hotter and move the fastest; they can form streams or rivers, or spread out across the landscape in lobes. Viscous flows are cooler and travel shorter distances, and can sometimes build up into lava domes or plugs; collapses of flow fronts or domes can form pyroclastic density currents (discussed later).

Most lava flows can be easily avoided by a person on foot, since they don't move much faster than walking speed, but a lava flow usually cannot be stopped or diverted. Because lava flows are extremely hot - between 1,000-2,000�C (1,800 - 3,600� F) - they can cause severe burns and often burn down vegetation and structures. Lava flowing from a vent also creates enormous amounts of pressure, which can crush or bury whatever survives being burned

Pyroclastic Density Currents

Pyroclastic density currents are an explosive eruptive phenomenon. They are mixtures of pulverized rock, ash, and hot gases, and can move at speeds of hundreds of miles per hour. These currents can be dilute, as in pyroclastic surges, or concentrated, as in pyroclastic flows. They are gravity-driven, which means that they flow down slopes.

A pyroclastic surge is a dilute, turbulent density current that usually forms when magma interacts explosively with water. Surges can travel over obstacles like valley walls, and leave thin deposits of ash and rock that drape over topography. A pyroclastic flow is a concentrated avalanche of material, often from a collapse of a lava dome or eruption column, which creates massive deposits that range in size from ash to boulders. Pyroclastic flows are more likely to follow valleys and other depressions, and their deposits infill this topography. Occasionally, however, the top part of a pyroclastic flow cloud (which is mostly ash) will detach from the flow and travel on its own as a surge.
Pyroclastic density currents of any kind are deadly. They can travel short distances or hundreds of miles from their source, and move at speeds of up to 1,000 kph (650 mph). They are extremely hot - up to 400�C (750�F). The speed and force of a pyroclastic density current, combined with its heat, mean that these volcanic phenomena usually destroy anything in their path, either by burning or crushing or both. Anything caught in a pyroclastic density current would be severely burned and pummeled by debris (including remnants of whatever the flow traveled over). There is no way to escape a pyroclastic density current other than not being there when it happens!

One unfortunate example of the destruction caused by pyroclastic density currents is the abandoned city of Plymouth on the Caribbean island of Montserrat. When the Soufri�re Hills volcano began erupting violently in 1996, pyroclastic density currents from eruption clouds and lava dome collapses traveled down valleys in which many people had their homes, and inundated the city of Plymouth. That part of the island has since been declared a no-entry zone and evacuated, although it is still possible to see the remains of buildings which have been knocked over and buried, and objects that have been melted by the heat of the pyroclastic density currents.

Pyroclastic Falls

Pyroclastic falls, also known as volcanic fallout, occur when tephra - fragmented rock ranging in size from mm to tens of cm (fractions of inches to feet) - is ejected from a volcanic vent during an eruption and falls to the ground some distance away from the vent. Falls are usually associated with Plinian eruptive columns, ash clouds or volcanic plumes. Tephra in pyroclastic fall deposits may have been transported only a short distance from the vent (a few meters to several km), or, if it is injected into the upper atmosphere, may circle the globe. Any kind of pyroclastic fall deposit will mantle or drape itself over the landscape, and will decrease in both size and thickness the farther away it is from its source.

Tephra falls are usually not directly dangerous unless a person is close enough to an eruption to be struck by larger fragments. The effects of falls can be, however. Ash can smother vegetation, destroy moving parts in motors and engines (especially in aircraft), and scratch surfaces. Scoria and small bombs can break delicate objects, dent metals and become embedded in wood. Some pyroclastic falls contain toxic chemicals that can be absorbed into plants and local water supplies, which can be dangerous for both people and livestock. The main danger of pyroclastic falls is their weight: tephra of any size is made up of pulverized rock, and can be extremely heavy, especially if it gets wet. Most of the damage caused by falls occurs when wet ash and scoria on the roofs of buildings causes them to collapse.
Pyroclastic material injected into the atmosphere may have global as well as local consequences. When the volume of an eruption cloud is large enough, and the cloud is spread far enough by wind, pyroclastic material may actually block sunlight and cause temporary cooling of the Earth's surface. Following the eruption of Mount Tambora in 1815, so much pyroclastic material reached and remained in the Earth's atmosphere that global temperatures dropped an average of about 0.5 �C (~1.0 �F). This caused worldwide incidences of extreme weather, and led 1816 to be known as 'The Year Without A Summer'.

Lahars

Lahars are a specific kind of mudflow made up of volcanic debris. They can form in a number of situations: when small slope collapses gather water on their way down a volcano, through rapid melting of snow and ice during an eruption, from heavy rainfall on loose volcanic debris, when a volcano erupts through a crater lake, or when a crater lake drains because of overflow or wall collapse.

Lahars flow like liquids, but because they contain suspended material, they usually have a consistency similar to wet concrete. They flow downhill and will follow depressions and valleys, but they can spread out if they reach a flat area. Lahars can travel at speeds of over 80 kph (50 mph) and reach distances dozens of miles from their source. If they were generated by a volcanic eruption, they may retain enough heat to still be 60-70�C (140-160�F) when they come to rest.

Lahars are not as fast or hot as other volcanic hazards, but they are extremely destructive. They will either bulldoze or bury anything in their path, sometimes in deposits dozens of feet thick. Whatever cannot get out of a lahar's path will either be swept away or buried. Lahars can, however, be detected in advance by acoustic (sound) monitors, which gives people time to reach high ground; they can also sometimes be channeled away from buildings and people by concrete barriers, although it is impossible to stop them completely.

Gases

Volcanic gases are probably the least showy part of a volcanic eruption, but they can be one of an eruption's most deadly effects. Most of the gas released in an eruption is water vapor (H₂O), and relatively harmless, but volcanoes also produce carbon dioxide (CO₂), sulfur dioxide (SO₂), hydrogen sulfide (H₂S), fluorine gas (F₂), hydrogen fluoride (HF), and other gases. All of these gases can be hazardous - even deadly - in the right conditions.

Carbon dioxide is not poisonous, but it displaces normal oxygen-bearing air, and is odorless and colorless. Because it is heavier than air, it collects in depressions and can suffocate people and animals who wander into pockets where it has displaced normal air. It can also become dissolved in water and collect in lake bottoms; in some situations, the water in those lakes can suddenly 'erupt' huge bubbles of carbon dioxide, killing vegetation, livestock and people living nearby. This was the case in the overturn of Lake Nyos in Cameroon, Africa in 1986, where an eruption of CO₂ from the lake suffocated more than 1,700 people and 3,500 livestock in nearby villages.

Sulfur dioxide and hydrogen sulfide are both sulfur-based gases, and unlike carbon dioxide, have a distinct acidic, rotten-egg smell. SO₂ can combine with water vapor in the air to form sulfuric acid (H₂SO₄), a corrosive acid; H₂S is also very acidic, and extremely poisonous even in small amounts. Both acids irritate soft tissues (eyes, nose, throat, lungs, etc.), and when the gases form acids in large enough quantities, they mix with water vapor to form vog, or volcanic fog, which can be dangerous to breathe and cause damage to the lungs and eyes. If sulfur-based aerosols reach the upper atmosphere, they can block sunlight and interfere with ozone, which have both short and long-term effects on climate.

One of the nastiest, although less common gases released by volcanoes is fluorine gas (F₂). This gas is yellowish brown, corrosive and extremely poisonous. Like CO₂, it is denser than air and tends to collect in low areas. Its companion acid, hydrogen fluoride (HF), is highly corrosive and toxic, and causes terrible internal burns and attacks calcium in the skeletal system. Even after visible gas or acid has dissipated, fluorine can be absorbed into plants, and may be able to poison people and animals for long periods following an eruption. After the 1783 eruption of Laki in Iceland, fluorine poisoning and famine caused the deaths of more than half the country's livestock and almost a quarter of its population.(geology.com)

Tailings Disposal to Sea

noreply@blogger.com (Meenviro) — Tue, 30 Nov 2010 02:23:05 PST

Critics of the disposal practices of the mine (tailings) into rivers and other water bodies, leading mining companies divert the discharge into the sea technique (called the method of sub-marine tailings disposal / STD).

Besides deemed to hide the impact it had, it turns out to sea tailings disposal method is much cheaper in terms of cost. They also promote that this method is a safe method with the assumption that there is a layer in the ocean thermocline which can hold the tailings in order to remain settled and did not rise to the surface and contaminate fish.

As the largest archipelago country in the world, with more than 17,500 islands and 80,000 km long coastline, the waters of Indonesia is a place to live and living marine resources diversity with the type of the richest coral reefs in the world (Wilkinson, 2000).

Plural tailings already known to contain various toxic materials originating from the oxidation reaction of rock and chemicals used in ore separation process. Disposal of tailings into the sea will cause sedimentation of sediment tailings and tailings spread into the wider sea area. All of these impacts will increasingly threaten and destroy the wealth of marine biodiversity, disrupt health (some heavy metal waste to accumulate in the food chain), and further impoverishing coastal communities and small islands are highly dependent on the sea.

In addition, 78% in Indonesian waters are shallow seas, then the method of sub-marine tailings disposal was also having a high risk for polluting the sea. Location of the Indonesian archipelago located between the Indian and Pacific Oceans, making the waters of Indonesia has a very high dynamics, which also affect the abundance of marine biodiversity, and dynamics of the physical condition of marine waters, such as the existence of the thermocline layer and the phenomenon of vertical mixing of sea water column (up -Welling).

WALHI STD consider this method can not be tolerated, as the methods of disposal of tailings directly into rivers and other water bodies. WALHI has called for the government to stop licensing the disposal of tailings into the sea and into other water bodies and requires the company to do the rehabilitation and clean up the damage and pollution that has caused

Water Flowing Through Ice Sheets Accelerates Warming, Could Speed Up Ice Flow

noreply@blogger.com (Meenviro) — Thu, 11 Nov 2010 08:49:01 PST

ScienceDaily (Nov. 3, 2010) -

Melt water flowing through ice sheets via crevasses, fractures and large drains called moulins can carry warmth into ice sheet interiors, greatly accelerating the thermal response of an ice sheet to climate change, according to a new study involving the University of Colorado at Boulder.

The new study showed ice sheets like the Greenland Ice Sheet can respond to such warming on the order of decades rather than the centuries projected by conventional thermal models. Ice flows more readily as it warms, so a warming climate can increase ice flows on ice sheets much faster than previously thought, said the study authors.

"We are finding that once such water flow is initiated through a new section of ice sheet, it can warm rather significantly and quickly, sometimes in just 10 years, " said lead author Thomas Phillips, a research scientist with Cooperative Institute for Research in Environmental Sciences. CIRES is a joint institute between CU-Boulder and the National Oceanic and Atmospheric Administration.

Phillips, along with CU-Boulder civil, environmental and architectural engineering Professor Harihar Rajaram and CIRES Director Konrad Steffen described their results in a paper published online in Geophysical Research Letters.

Conventional thermal models of ice sheets do not factor in the presence of water within the ice sheet as a warming agent, but instead use models that primarily consider ice-sheet heating by warmer air on the ice sheet surface. In water's absence, ice warms slowly in response to the increased surface temperatures from climate change, often requiring centuries to millennia to happen.

But the Greenland ice sheet is not one solid, smooth mass of ice. As the ice flows towards the coast, grating on bedrock, crevasses and new fractures form in the upper 100 feet of the ice sheet.

Melt water flowing through these openings can create "ice caves" and networks of "pipes" that can carry water through the ice and spreading warmth, the authors concluded.

To quantify the influence of melt water, the scientists modeled what would happen to the ice sheet temperature if water flowed through it for eight weeks every summer -- about the length of the active melt season. The result was a significantly faster-than-expected increase in ice sheet warming, which could take place on the order of years to decades depending on the spacing of crevasses and other "pipes" that bring warmer water into the ice sheet in summer.

"The key difference between our model and previous models is that we include heat exchange between water flowing through the ice sheet and the ice," said Rajaram.

Several factors contributed to the warming and resulting acceleration of ice flow, including the fact that flowing water into the ice sheets can stay in liquid form even through the winter, slowing seasonal cooling. In addition, warmer ice sheets are more susceptible to increases of water flow, including the basal lubrication of ice that allows ice to flow more readily on bedrock.

A third factor is melt water cascading downward into the ice, which warms the surrounding ice. In this process the water can refreeze, creating additional cracks in the more vulnerable warm ice, according to the study.

Taken together, the interactions between water, temperature, and ice velocity spell even more rapid changes to ice sheets in a changing climate than currently anticipated, the authors concluded. After comparing observed temperature profiles from Greenland with the new model described in the paper, the authors concluded the observations were unexplainable unless they accounted for warming.

"The fact that the ice temperatures warm rather quickly is really the key piece that's been overlooked in models currently being used to determine how Greenland responds to climate warming," Steffen said. "However, this process is not the 'death knell' for the ice sheet. Even under such conditions, it would still take thousands of years for the Greenland ice sheet to disappear, Steffen said.

This study was funded by NASA's Cryosphere Science Program (http://www.sciencedaily.com).

How Ozone Pollution Works

noreply@blogger.com (Meenviro) — Mon, 08 Nov 2010 21:55:49 PST

Ozone can also be found in the troposphere, the lowest layer of the atmosphere.

Tropospheric ozone (often termed "bad" ozone) is man-made, a result of air pollution from internal combustion engines and power plants. Automobile exhaust and industrial emissions release a family of nitrogen oxide gases (NOx) and volatile organic compounds (VOC), by-products of burning gasoline and coal. NOx and VOC combine chemically with oxygen to form ozone during sunny, high-temperature conditions of late spring, summer and early fall. High levels of ozone are usually formed in the heat of the afternoon and early evening, dissipating during the cooler nights.

Logam berat dan lingkungan

noreply@blogger.com (Meenviro) — Fri, 05 Nov 2010 21:10:00 PDT

S esungguhnya, istilah logam berat hanya ditujukan kepada logam yang mempunyai berat jenis lebih besar dari 5 g/cm3. Namun, pada kenyataannya, unsur-unsur metaloid yang mempunyai sifat berbahaya juga dimasukkan ke dalam kelompok tersebut. Dengan demikian, yang termasuk ke dalam kriteria logam berat saat ini mencapai lebih kurang 40 jenis unsur. Beberapa contoh logam berat yang beracun bagi manusia adalah: arsen (As), kadmium (Cd), tembaga (Cu), timbal (Pb), merkuri (Hg), nikel (Ni), dan seng (Zn).

Arsen
Arsen (As) atau sering disebut arsenik adalah suatu zat kimia yang ditemukan sekitar abad-13. Sebagian besar arsen di alam merupakan bentuk senyawa dasar yang berupa substansi inorganik. Arsen inorganik dapat larut dalam air atau berbentuk gas dan terpapar pada manusia. Menurut National Institute for Occupational Safety and Health (1975), arsen inorganik bertanggung jawab terhadap berbagai gangguan kesehatan kronis, terutama kanker. Arsen juga dapat merusak ginjal dan bersifat racun yang sangat kuat.

Merkuri
Merkuri (Hg) atau air raksa adalah logam yang ada secara alami, merupakan satu-satunya logam yang pada suhu kamar berwujud cair. Logam murninya berwarna keperakan, cairan tak berbau, dan mengkilap. Bila dipanaskan sampai suhu 3570C, Hg akan menguap. Selain untuk kegiatan penambangan emas, logam Hg juga digunakan dalam produksi gas klor dan soda kaustik, termometer, bahan tambal gigi, dan baterai.
Walaupun Hg hanya terdapat dalam konsentrasi 0,08 mg/kg kerak bumi, logam ini banyak tertimbun di daerah penambangan. Hg lebih banyak digunakan dalam bentuk logam murni dan organik daripada bentuk anorganik. Logam Hg dapat berada pada berbagai senyawa. Bila bergabung dengan klor, belerang, atau oksigen, Hg akan membentuk garam yang biasanya berwujud padatan putih. Garam Hg sering digunakan dalam krim pemutih dan krim antiseptik.

Timbal
Logam timbal (Pb) merupakan logam yang sangat populer dan banyak dikenal oleh masyarakat awam. Hal ini disebabkan oleh banyaknya Pb yang digunakan di industri nonpangan dan paling banyak menimbulkan keracunan pada makhluk hidup. Pb adalah sejenis logam yang lunak dan berwarna cokelat kehitaman, serta mudah dimurnikan dari pertambangan.
Dalam pertambangan, logam ini berbentuk sulfida logam (PbS), yang sering disebut galena. Senyawa ini banyak ditemukan dalam pertambangan di seluruh dunia. Bahaya yang ditimbulkan oleh penggunaan Pb ini adalah sering menyebabkan keracunan.

Menurut Darmono (1995), Pb mempunyai sifat bertitik lebur rendah, mudah dibentuk, mempunyai sifat kimia yang aktif, sehingga dapat digunakan untuk melapisi logam untuk mencegah perkaratan. Bila dicampur dengan logam lain, membentuk logam campuran yang lebih bagus daripada logam murninya, mempunyai kepadatan melebihi logam lain.
Logam Pb banyak digunakan pada industri baterai, kabel, cat (sebagai zat pewarna), penyepuhan, pestisida, dan yang paling banyak digunakan sebagai zat antiletup pada bensin. Pb juga digunakan sebagai zat penyusun patri atau solder dan sebagai formulasi penyambung pipa yang mengakibatkan air untuk rumah tangga mempunyai banyak kemungkinan kontak dengan Pb (Saeni, 1997).

Logam Pb dapat masuk ke dalam tubuh melalui pernapasan, makanan, dan minuman. Logam Pb tidak dibutuhkan oleh manusia, sehingga bila makanan tercemar oleh logam tersebut, tubuh akan mengeluarkannya sebagian. Sisanya akan terakumulasi pada bagian tubuh tertentu seperti ginjal, hati, kuku, jaringan lemak, dan rambut.

Tembaga
Tidak seperti logam-logam Hg, Pb, dan Cd, logam tembaga (Cu) merupakan mikroelemen esensial untuk semua tanaman dan hewan, termasuk manusia. Logam Cu diperlukan oleh berbagai sistem enzim di dalam tubuh manusia. Oleh karena itu, Cu harus selalu ada di dalam makanan. Yang perlu diperhatikan adalah menjaga agar kadar Cu di dalam tubuh tidak kekurangan dan juga tidak berlebihan.
Kebutuhan tubuh per hari akan Cu adalah 0,05 mg/kg berat badan. Pada kadar tersebut tidak terjadi akumulasi Cu pada tubuh manusia normal. Konsumsi Cu dalam jumlah yang besar dapat menyebabkan gejala-gejala yang akut.

Logam Cu yang digunakan di pabrik biasanya berbentuk organik dan anorganik. Logam tersebut digunakan di pabrik yang memproduksi alat-alat listrik, gelas, dan zat warna yang biasanya bercampur dengan logam lain seperti alloi dengan Ag, Cd, Sn, dan Zn.
Garam Cu banyak digunakan dalam bidang pertanian, misalnya sebagai larutan “Bordeaux” yang mengandung 1-3% CuSO4 untuk membasmi jamur pada sayur dan tumbuhan buah. Senyawa CuSO4 juga sering digunakan untuk membasmi siput sebagai inang dari parasit, cacing, dan juga mengobati penyakit kuku pada domba (Darmono, 1995).

How Batteries Work

noreply@blogger.com (Meenviro) — Thu, 04 Nov 2010 20:03:00 PDT

A voltaic pile

The first battery was created by Alessandro Volta in 1800. To create his battery, he made a stack by alternating layers of zinc, blotting paper soaked in salt water, and silver. This arrangement was known as a voltaic pile. The top and bottom layers of the pile must be different metals. If you attach a wire to the top and bottom of the pile, you can measure a voltage and a current from the pile. The pile can be stacked as high as you like, and each layer will increase the voltage by a fixed amount.

In the 1800s, before the invention of the electrical generator (the generator was not invented and perfected until the 1870s), the Daniell cell was extremely common for operating telegraphs and doorbells. The Daniell cell is also known by three other names:

Crowfoot cell (because of the typical shape of the zinc electrode)
Gravity cell (because gravity keeps the two sulfates separated)
Wet cell (because it uses liquids for the electrolytes, as opposed to the modern dry cell)

The Daniell Cell

The Daniell cell is a wet cell consisting of copper and zinc plates and copper and zinc sulfates. To make the Daniell cell, the copper plate is placed at the bottom of a glass jar. Copper sulfate solution is poured over the plate to half-fill the jar. Then a zinc plate is hung in the jar and a zinc sulfate solution is poured very carefully into the jar. Copper sulfate is denser than zinc sulfate, so the zinc sulfate "floats" on top of the copper sulfate. Obviously, this arrangement does not work very well in a flashlight, but it works fine for stationary applications.(source: http://electronics.howstuffworks.com)

How Batteries Work

noreply@blogger.com (Meenviro) — Wed, 03 Nov 2010 19:48:00 PDT

ABa�tteries are all over the place -- in our cars, our PCs, laptops, portable MP3 players and cell phones. battery is essentially a can full of chemicals that produce electrons. Chemical reactions that produce electrons are called electrochemical reactions. In this article, you'll learn all about batteries -- the basic concept at work, the actual chemistry going on inside a battery, rechargeable versions, what the future holds for batteries and possible power sources that could replace them.

If you look at any battery, you'll notice that it has two terminals. One terminal is marked (+), or positive, while the other is marked (-), or negative. In an AA, C or D cell (normal flashlight batteries), the ends of the battery are the terminals. In a large car battery, there are two heavy lead posts that act as the terminals.

Electrons collect on the negative terminal of the battery. If you connect a wire between the negative and positive terminals, the electrons will flow from the negative to the positive terminal as fast as they can (and wear out the battery very quickly -- this also tends to be dangerous, especially with large batteries, so it is not something you want to be doing). Normally, you connect some type of load to the battery using the wire. The load might be something like a light bulb, a motor or an electronic circuit like a radio.

�Inside the battery itself, a chemical reaction produces the electrons. The speed of electron production by this chemical reaction (the battery's internal resistance) controls how many electrons can flow between the terminals. Electrons flow from the battery into a wire, and must travel from the negative to the positive terminal for the chemical reaction to take place. That is why a battery can sit on a shelf for a year and still have plenty of power -- unless electrons are flowing from the negative to the positive terminal, the chemical reaction does not take place. Once you connect a wire, the reaction starts. The ability to harness this sort of reaction started with the voltaic pile.
Next, we'll check out how a voltaic pile works and look at other types of batteries.(source: http://electronics.howstuffworks.com)

Hakikat Gunung di Hadapan Allah

noreply@blogger.com (Meenviro) — Tue, 02 Nov 2010 20:59:00 PDT

Seperti telah disinggung di muka, bahwa gunung banyak diungkap di dalam ayat-ayat Al-Qur’an, tetapi sampai sejauh mana gunung ini dianggap penting di hadapan Allah? Dalam Al-Qur’an surah Al-Baqarah (2:63) disebutkan: “Dan ingatlah, ketika Kami mengambil janji dari kamu dan Kami angkatkan gunung di atasmu:” peganglah teguh-teguh apa yang Kami berikan kepadamu dan ingatlah selalu apa yang ada di dalamnya, agar kamu bertaqwa”.
Dalam kehidupan sehari-hari kita juga menyaksikan, baik di negara muslim maupun non-muslim; bahwasannya apabila kita bersaksi atau menyatakan kebenaran terhadap suatu kesaksian dan menyatakan kesungguhan terhadap suatu janji yang kita ucapkan, maka biasanya kita disumpah di bawah kitab suci. Ayat tersebut di atas mengisahkan tentang Bani Israel yang disumpah oleh Allah dengan mengangkat sebuah gunung (Jabal Thur), agar Bani Israel tidak melanggar perjanjian dengan Tuhan. Ini berarti bahwa gunung memiliki pengertian khusus, karena gunung dijadikan saksi atas janji yang diucapkan oleh bangsa Bani Israel.

Pandangan IPTEK terhadap Gunung
Dalam ilmu kebumian (geologi), gunung -lebih khusus lagi gunungapi-, sudah menjadi bagian yang tak terpisahkan dari perkembangan ilmu kebumian itu sendiri. Teori yang paling fundamental, mutakhir dan dipercaya mampu menjelaskan berbagai fenomena perubahan bumi adalah “Teori Tektonik Lempeng” atau “Theory of Plate Tectonic”. Teori ini berkembang sejak akhir tahun 1960-an dan dapat dianggap sebagai awal revolusi ilmu bumi. Sejak itu, para ilmuwan berlomba-lomba melakukan verifikasi dan melengkapi teori ini, sehingga saat ini kita dapat memahami lebih baik bagaimana proses internal planet bumi melalui Teori Tektonik Lempeng, baik kejadian masa lalu maupun masa yang akan datang.
Pada intinya teori ini menyatakan, bahwa bagian luar dari bumi (kulit bumi) yang kita tempati ini terdiri atas lempengan-lempengan padat yang kita sebut sebagai kerak bumi, dengan bentuk dan potongan yang tidak beraturan mirip dengan “Jigsaw Puzzle”. Berdasarkan sifatnya kerak bumi dapat dibedakan menjadi 2 (dua) yakni Kerak Benua, yang tebal tapi ringan dan Kerak Samudra yang tipis tapi berat. Lempengan ini bertumpu (mengapung) di atas massa yang cair (magma) di mana antar lempeng tersebut saling bersentuhan satu sama lain. Lempeng-lempeng ini tidak tinggal diam, artinya selalu bergerak dan batas persentuhannya membentuk pola pergerakan (Gambar 11.1) :
Ø Saling mendekat, akibatnya akan saling bertumbukan
Ø Saling menjauh, akibatnya terjadi pemekaran; dan
Ø Saling berpapasan.

Gambar Bagian-bagian utama potongan kulit bumi, yang masing-masing saling bergerak.

Manusia telah banyak mendapatkan keuntungan, tentu saja di samping kerugiannya, dari gaya-gaya yang bekerja di bumi sebagai konsekuensi dari tektonik lempeng ini. Keberadaan mineral-mineral berharga seperti intan, emas, perak, minyak bumi, plutonium, tanah yang subur, serta barang-barang yang kita gunakan sehari-hari seperti gelas, piring, radio, TV, mobil, pesawat terbang bahkan chip komputer sekali pun adalah produk mineral yang telah diolah untuk kesejahteraan manusia. Meskipun demikian, dengan atau tanpa peringatan terlebih dahulu, gempa bumi dan letusan gunungapi adalah bentuk-bentuk pelepasan energi bumi sedemikian dahsyat dan tiada pernah setara dengan segala sesuatu yang pernah dibuat oleh manusia.

Untuk memahami keberadaan gunung dan gunung api, kita perlu memahami proses internal bumi terutama dari sisi pandang teori tektonik lempeng.(Yunus Ashari, Ir, MT)

Bumi yang kesepian

noreply@blogger.com (Meenviro) — Sun, 31 Oct 2010 20:49:00 PDT

Sebagai suatu sistem, tata surya kita berpusat kepada matahari, merupakan bintang menengah-sedang yang berdiameter sekitar 1.400.000 km; dikelilingi oleh 9 planet, 31 bulan dan lebih dari 30.000 asteroid serta meteor dan komet yang tidak terhitung jumlahnya.
Kita bisa membuat pengandaian; jika matahari kita adalah benda sebesar bola basket, maka bumi seperti kepala jarum pentul yang berjarak 27 meter (84 ft) dari bola basket, dan pluto berada pada jarak sekitar 0,915 km. Bintang terdekat dari sistem tata surya kita akan berada pada jarak 6.500 km
dari matahari. Cahaya bintang tersebut akan tertangkap oleh mata kita setelah menempuh perjalanan 4,21 tahun; di mana seperti kita ketahui kecepatan cahaya adalah 300.000 km/det.

Matahari kita adalah termasuk bintang kecil-menengah, jangkauan energinya hanya menyebabkan bumi kita terasa hangat, mampu mensirkulasikan udara dan air sehingga dapat mendukung adanya kehidupan (manusia, tumbuhan dan hewan) di planet ini. Jarak bumi terhadap matahari adalah sekitar 150 juta kilometer dan hanya menyerap energi matahari sekitar 1/2.200.000-nya.
Hal ini sangat menguntungkan, karena setiap meter persegi permukaan matahari memiliki energi sekitar 15 juta kalori/detik, cukup untuk membuat seluruh alir yang ada di lautan, sungai dan danau mendidih.

Beberapa bintang besar memiliki energi yang sangat-sangat besar; 6 hari bersinarnya sebanding dengan energi yang dikeluarkan oleh matahari selama 1 juta tahun, hal ini dapat dimengerti karena diameternya pun 2.700 kali lebih besar dari matahari kita. Temperatur permukaan matahari diperkirakan sekitar 5.500^oC dan sekitar 14 juta derajad Celcius di bagian tengahnya.
Gambaran tersebut hanya tata surya kita, yang merupakan bagian kecil dari suatu kumpulan bintang (galaksi) Andromeda (Milky Way), di mana di dalamnya terdiri dari sekitar 100 milyar bintang yang statusnya seperti matahari kita. Di alam semesta ini, kemungkinan dijumpai milyaran galaksi.

Pertanyaannya adalah mungkinkah salah satu bintang alam semesta raya ini memiliki planet seperti bumi?

Sampai hari ini, manusia belum mampu menjawab pertanyaan tersebut. Bahkan terhadap planet terdekat kita pun yaitu Mars, kita hanya tahu sedikit. Sehingga dapat dimengerti, jika bumi kita adalah sebuah planet kecil yang kesepian di tengah jagad raya.

Planet Earth

noreply@blogger.com (Meenviro) — Thu, 28 Oct 2010 20:50:00 PDT

The Earth, which is located three planets from the Sun, is the only planet in the universe known to support any kind of life. The Earth is estimated to be approximately 4.57 billion years old. The moon followed not long after.

The Earth rotates around its own north to south axis once every 23 hours, 56 minutes and 4.091 seconds (one day), and around the Sun once every 365.2564 days (one year).

The Earth formed when the initial molten lava mass cooled and formed a solid outer crust

The Earth’s approximation to the Sun and ability to absorb its solar energy allowed for photosynthesis to occur. This began the accumulation and storage of oxygen in the Earth’s atmosphere and the development of what we now know as the ozone layer. Early eukaryotic life on Earth soon followed.

With the complete formation of the ozone layer, which blocked all harmful ultraviolet radiation from the Sun, multicellular life began to slowly populate the planet. Following several major catastrophic life extinctions, mankind’s first ancestors slowly began to evolve, beginning the early stages of what has lead to the world as we know it today. (http://www.space.com/earth/)

Elemen Sistem Airtanah

noreply@blogger.com (Meenviro) — Mon, 25 Oct 2010 08:55:00 PDT

Berdasarkan sifat dan sikapnya terhadap air, maka batuan dapat dikelompokkan menjadi 4 (empat) macam, yaitu:

Akifer adalah batuan yang dapat menyimpan dan meloloskan air di dalam tanah, dicirikan dengan nilai porositas dan permebilitas yang tinggi. Di Cekungan Bandung, batuan yang dapat bertindak sebagai akifer umumnya adalah lapisan batuan hasil letusan gunungapi.
Akiklud dibentuk oleh batuan atau sedimen yang bertindak sebagai penghalang (barier) bagi aliran airtanah. Akiklud tersusun oleh batuan atau sedimen yang memiliki sifat permeabilitas yang rendah, seperti pada serpih atau lempung. batuan yang bersifat akiklud dapat menyimpan air, tetapi tidak dapat mengalirkan dalam jumlah yang berarti.
Akitar, adalah batuan yang mempunyai susunan sedemikian rupa, sehingga dapat menyimpan air tetapi hanya dapat mengalirkannya dalam jumlah yang terbatas, contohnya adalah pasir lempungan, atau lempung pasiran.

Akifug, adalah lapisan yang kebal terhadap air (impermeable layer), yaitu batuan yang tidak dapat menyimpan dan mengalirkan air; contohnya adalah batuan beku yang tidak memiliki rekahan

Akifer berada pada zona jenuh (saturated zone), jika seluruh pori (rongga) antar butiran terisi sepenuhnya oleh air. Zona jenuh umumnya ditutupi oleh zona tidak jenuh (unsaturated zone), di mana rongga pori hanya sebagian saja yang terisi airwhere. Bagian atas dari zona jenuh atau batas bawah zona tidak jenuh disebut sebagai muka airtanah (water table).
Akifer dapat dibagi menjadi beberapa jenis, yaitu akifer terbuka atau akifer tidak tertekan (unconfined) dan akifer tertekan (artesis atau confined). Pada akifer tidak tertekan, air masuk (infiltrasi) melalui tanah dan batuan atau sedimen yang permeabel (porous), dapat berasal dari air hujan, sungai atau danau dan lain-lain. Peristiwa tersebut dikenal sebagai recharge.
Akifer tertekan (artesian) tertutupi oleh akiklud yang masuk melalui proses infiltasi dengan cara yang sama melalui akifer itu sendiri di bagian yang tersingkap di permukaan (lihat Gambar ). Bila dari zona recharge, di elevasi tinggi, air mengisi lapisan akifer yang telah terlipatkan, maka tekanan yang diterima oleh kolom air akan meningkat. Jika lapisan akifer tersebut tertembus oleh sumur bor, maka air akan mengalir dari akifer dengan sendirinya ke atas permukaan (muncrat). Sumur bor yang menembus lapisan akifer tertekan disebut sebagai sumur artesis (flowing well)

Diagram akifer tertekan. Akifer tertekan di bawah lapisan impermeable (akiklud). Muka Air tanah yang naik melewati posisi topografi akan menghasilkan sumur artesis, akibat tekanan tinggi pada kolom akuifer

Airtanah mengalir jauh lebih lambat dari pada aliran air sungai dan dikontrol oleh sifat fisik dari batuannya. Kecepatan aliran airtanah biasanya diukur dalam satuan mm/tahun, yang jauh berbeda dari pada pengukuran kecepatan arus sungai, yang biasanya dinyatakan dalam m/detik.

Sumur Artesis, sumur dalam yang dapat mengalirkan air dengan sendiri (self flowing well)

Arah aliran airtanah sebenarnya adalah ke bawah karena pengaruh gravitasi.
Secara alamiah air yang keluar meninggalkan sistem airtanah (discharge) umumnya terjadi dalam tiga cara, yaitu:
a) Mengisi sungai, jika kondisi muka airtanah lebih tinggi dari pada muka air sungai.
b) Airtanah keluar di daerah sekitar pantai menuju laut
c) Mata air, airtanah yang mengalir dan memotong bidang tidak selaras, misalnya rekahan, patahan, atau terpotong bidang topografi, selanjutnya muncul di permukaan membentuk mata air. Mata air terbentuk jika muka airtanah berpotongan dengan muka tanah. Kejadian ini umumnya berkaitan dengan system rekahan, yang nantinya dapat dilalui oleh aliran airtanah.

	Aliran air di sungai diukur dalam satuan m/detik. Airtanah dapat mengisi sungai melalui proses rembesan (Foto: Colorado School of Mine).
	Mata air membentuk air terjun, mengalir keluar dari rekahan yang terjadi pada lapisan batuan dan terpotong oleh topografi (muka tanah), dijumpai di Thunder River - Grand Canyon, Arizona. (Foto Dr. Ira Sasowsky, University of Akron).

Yunus Ashari, Ir, MT

Sumber kontaminan logam berat

noreply@blogger.com (Meenviro) — Sat, 23 Oct 2010 21:17:00 PDT

Kandungan alamiah logam pada lingkungan dapat berubah-ubah, tergantung pada kadar pencemaran oleh ulah manusia atau perubahan alam, seperti erosi. Kandungan logam tersebut dapat meningkat bila limbah perkotaan, pertambangan, pertanian, dan perindustrian yang banyak mengandung logam berat masuk ke lingkungan.

Dari berbagai limbah tersebut, umumnya yang paling banyak mengandung logam berat adalah limbah industri. Hal ini disebabkan senyawa atau unsur logam berat dimanfaatkan dalam berbagai industri, baik sebagai bahan baku, katalisator, maupun sebagai bahan tambahan.
Penyebab utama logam berat menjadi bahan pencemar berbahaya adalah karena sifatnya yang tidak dapat dihancurkan (nondegradable) oleh organisme hidup yang ada di lingkungan. Akibatnya, logam-logam tersebut terakumulasi ke lingkungan, terutama mengendap di dasar perairan membentuk senyawa kompleks bersama bahan organik dan anorganik secara adsorbsi dan kombinasi.

1. Arsen

Arsen banyak ditemukan di dalam air tanah. Hal ini disebabkan arsen merupakan salah satu mineral yang memang terkandung dalam susunan batuan bumi. Arsen dalam air tanah terbagi dalam dua bentuk, yaitu bentuk tereduksi, terbentuk dalam kondisi anaerobik, sering disebut arsenit. Bentuk lainnya adalah bentuk teroksidasi, terjadi pada kondisi aerobik, umum disebut sebagai arsenat (Jones, 2000).

2. Hg

Hg anorganik (logam dan garam Hg) terdapat di udara dari deposit mineral dan dari area industri. Logam Hg yang ada di air dan tanah terutama berasal dari deposit alam, buangan limbah, dan akitivitas vulkanik. Logam Hg dapat pula bersenyawa dengan karbon membentuk senyawa Hg organik.

Senyawa Hg organik yang paling umum adalah metil merkuri, yang terutama dihasilkan oleh mikroorganisme (bakteri) di air dan tanah. Bila bakteri itu kemudian termakan oleh ikan, ikan tersebut cenderung memiliki konsentrasi merkuri yang tinggi.

Logam ini digunakan secara luas untuk mengekstrak emas dari bijihnya, baik sebelum maupun sesudah proses sianidasi digunakan. Ketika Hg dicampur dengan bijih tersebut, Hg akan membentuk amalgam dengan emas atau perak. Untuk mendapatkan emas dan perak, amalgam tersebut harus dibakar untuk menguapkan merkurinya.

Para penambang emas tradisional menggunakan merkuri untuk menangkap dan memisahkan butir-butir emas dari butir-butir batuan. Endapan Hg ini disaring menggunakan kain untuk mendapatkan sisa emas. Endapan yang tersaring kemudian diremas-remas dengan tangan. Air sisa-sisa penambangan yang mengandung Hg dibiarkan mengalir ke sungai dan dijadikan irigasi untuk lahan pertanian.

Selain itu, komponen merkuri juga banyak tersebar di karang, tanah, udara, air, dan organisme hidup melalui proses fisik, kimia, dan biologi yang kompleks. Walaupun mekanisme keracunan merkuri di dalam tubuh belum diketahui dengan jelas, beberapa hal mengenai daya racun merkuri dapat dijelaskan sebagai berikut (Fardiaz, 1992):

3. Pb (timbal)

Sumber kontaminan timbal (Pb) terbesar dari buatan manusia adalah bensin beraditif timbal untuk bahan bakar kendaraan bermotor. Diperkirakan 65 persen dari semua pencemaran udara disebabkan emisi yang dikeluarkan oleh kendaraan bermotor.

4. Cu (tembaga)

Cemaran logam Cu pada bahan pangan pada awalnya terjadi karena penggunaan pupuk dan pestisida secara berlebihan. Meskipun demikian, pengaruh proses pengolahan akan dapat mempengaruhi status keberadaan tersebut dalam bahan pangan.

Porositas dan Permeabilitas Airtanah

noreply@blogger.com (Meenviro) — Fri, 22 Oct 2010 08:45:00 PDT

A irtanah adalah air terkandung di dalam batuan dan berada di bawah permukaan tanah. Keberadaan airtanah adalah sekitar 40 kali dari jumlah air yang terdapat di danau-danau dan sungai-sungai di permukaan bumi. Distribusi airtanah tergantung kepada porositas dan permeabilitas suatu batuan terutama di dalam batuan sedimen. Batuan sedimen memiliki ruangan di antara butirannya (pori-pori batuan), di dalam rekahannya atau di dalam rongga-rongga hasil pelarutan (pada batugamping), yang memungkinkan untuk diisi air.

Porositas adalah kemampuan suatu batuan atau sedimen untuk menyimpan air. Porositas dapat mencapai lebih dari 40% dari volume batuan/sedimen. Porositas umumnya tinggi pada sedimen yang tidak atau belum termampatkan (pasir, kerakal) daripada batuannya (batupasir, konglomerat) yang telah mengalami pemampatan (lithifikasi)

Permeabilitas adalah kemampuan suatu batuan/sedimen untuk mengalirkan air.

Ilustrasi yang memperlihatkan bagaimana air mengalir melalui ruang antar butir (pori batuan). Tidak semua pori, beberapa dari padanya terkunci (interlocking), misalnya oleh semen perekat butiran.

Demonstrasi cara penentuan Porositas tanah

	Demonstrasi Penentuan Porositas Sediakan dua tabung gelas @ 1000 ml. sebelah kiri diisi dengan 1000 ml pasir, sedangkan sebelah kanan diisi dengan 500 ml air. Air akan dituangkan secara pelahan-lahan ke dalam gelas pasir, hingga pasir menjadi jenuh.
	Tinggi air gelas kanan berkurang dari 500 ml menjadi 150 ml, karena 350 ml air telah diisikan ke dalam gelas pasir hingga pasir menjadi jenuh. Berdasarkan hal ini dapat diketahui bahwa terdapat rongga di antara butiran pasir sebesar 350 ml/1000 ml =35%.

Yunus Ashari, Ir, MT

Faham Geosentris

noreply@blogger.com (Meenviro) — Tue, 19 Oct 2010 20:42:00 PDT

Adanya kenyataan bahwa matahari terbit di timur dan tenggelam di barat. Hal ini tidaklah mengherankan bagi orang sejak dahulu, sehingga mereka berpikiran bahwa bumi-lah sebagai pusat tata surya, di mana benda-benda yang lain terlihat seperti mengelilingi bumi (Geo~bumi, centris ~ lingkaran / pusat orbit). Sebagaimana filsuf Yunani, Aristoteles, percaya bahwa:

¨ Bumi adalah pusat alam semesta
¨ Planet-planet yang terlihat oleh mata (Mercurius, Venus, Mars, Jupiter, Saturnus) berputar mengelilingi bumi
¨ Demikian juga halnya dengan bintang-bintang, kesemuanya berputar mengelilingi bumi.

Seorang filsuf Yunani lain, Aristarchus, menghitung ukuran relatif bumi dan matahari, dan didapatkan bahwa volume matahari jauh lebih besar dari bumi. Berdasarkan hal itu dia menyimpulkan bahwa bukan tidak mungkin bumi yang berputar mengelilingi matahari di dalam suatu orbit heliosentrik. Tetapi, ide tersebut tidak bersambut dan hampir terlupakan selama hampir 1800 tahun.

Model geosentris ini menjadi semakin rumit menjelang abad XV, akibat Aristoteles mengukur secara detil gerakan planet.

Ptolomeus, memperbaharui pandangan Aristoteles. Berdasarkan pengamatan Ptolomeus, diketahui adanya gerakan orbit semu dari planet-planet yang kasat mata, sehingga disimpulkan bahwa di samping planet mengelilingi bumi, planet tersebut juga memerlukan sebuah putaran kecil, yang tidak mampu dijelaskan dengan pasti. Orbit kecil sebagai tambahan ini disebut sebagai Epicycle.

Titik terdalam rekayasa manusia dan sentuhan alam

noreply@blogger.com (Meenviro) — Sun, 17 Oct 2010 14:05:09 PDT

Penyelamatan 33 penambang Chile yang terjebak di lubang tambang emas bawah tanah San Jose dengan kedalaman 688 m menjadi suatu drama penyelamatan tersulit yang menggugah dunia.

Chile, Rabu (13 Oktober 2010) menjadi babak baru peradaban dunia dibidang tambang bawah tanah, yaitu dengan diselamatkannya 33 penambang yang terjebak dalam lubang tambang sedalam 668 m. Segala upaya teknik terkini dibidang pertambangan dengan didukung teknologi ruang angkasa yang diwakili oleh NASA, telah berhasil dengan sempurna tanpa korban jiwa. Kompilasi ketelitian para insiyur Chile dengan NASA dalam membuat jalur baru evakuasi secara vertikal lewat pipa telah menunjukkan bahwa teknologi merupakan salah satu alat penyelamatan yang paling handal dan terpercaya selain faktor kehendak Tuhan. Demikian juga dengan peralatan-peralatan pendukungnya seperti Kapsul Phonix (hasil modifikasi insiyur Chile dan NASA) serta pakaian khusus tim penolong yang dibuat oleh Badan Antariksa Jepang.

Tambang emas San Jose dengan kedalaman 688 m dalam kondisi jalur yang berkelok mempunyai kedalaman yang panjang, namun kalau di ukur secara vertikal Tambang San Jose bukanlah bukaan terdalam yang pernah dibuat oleh manusia maupun oleh aktifitas alam.

Kolo Superdeep Borehole.

Merupakan salah satu pemboran yang berada di Semenanjung Kola Rusia. Pemimpin proyek ini adalah Menteri Geologi Rusia. Pengeboran dimulai pada masa kejayaan Uni Sovietpada 19 Mei 1970. Pada saat itu semua tim konstruksi diperlakukan layaknya seorang pejabat tinggi, yaitu dengan fasilitas mewah seperti apartemen dengan gaji seorang profesor selama satu tahun.

Namun Kola Superdeep Borehole diberhentikan 1994. Terakhir pencapaian kedalaman pada tahun 1984 yaitu 12 km. Pemberhentian diberhentikan dengan alasan kekurangan dana.

alung Mariana.

Palung ini terletak di dasar barat laut Samudra pasifik, sebelah timur Kepulauan Mariana berdekatan dengan Jepang. Palung ini merupakan tempat terjadinya subduksi antara Lempeng Pasifik dan Lempeng Filipina. Kedalaman dari palung ini lebih tinggi dari Gunung Everest yang dikukur dari permukaan laut. Palung ini mempunyai kedalaman 10.911 meter (35.798 kaki) dibawah permukaan laut. Dari pusat bumi, palung ini berjarak 6.366,4 km. Pertama kali palung ini di teliti tahun 1951 oleh Angkatan laut Britania, Challenger II.

Deep Water Horizon

Merupakan pemboran minyak yang berlokasi berada di pantai Louisiana, Amerika Serikat AS), milik British Petroleum pada tanggal 22 April 2010. Keadalaman lubang pemboran 12 km di bawah permukaan laut. Pada Mei 2010, Pipa minyak yang berada di lepas pantai Louisiana itu meledak, yang menyebabkan kebocoran minyak mentah yang mencemari lautan hingga ke Pantai Louisiana.

Pengeboran Nankai

Pengeboran yang dilakukan oleh para ilmuwan dunia seperti dari Jepang, Amerika dan negara-negara Eropa. Lokasi pemboran di laut dalam Chikyu, dengan kedalaman akhir 8.000 meter dibawah laut.

Tambamg emas Tautona

Tambang emas ini berlokasi di Afrika Selatan. Tau Tona (Tautona) mempunyai arti singa besar yang diambil dari bahasa lokal yaitu bahasa Sotho. Awal mula tambang ini dibangun oleh Amerika dan Inggris yaitu perusahaan Anglo Anerican Corporation. Tambang ini mulai beroperasi tahun 1954. Banyak kendala dalam konstruksinya diantaranya sering terjadi gempa tektonik kecil ( 10 gempa tektonik kecil/hari). Tambang ini merupakan tambang emas terdalam didunia dengan kedalaman mencapai 3,9 km dari permukaan laut. Suhu dalam tambang rata-rata mencapai 40 derajat celsius, pada lokasi lorong terdalam bisa m encapai 50 derajat celsius.

Energi Bumi

noreply@blogger.com (Meenviro) — Sat, 16 Oct 2010 18:14:34 PDT

Dalam sistem bumi kita mengenal adanya Gradien geotermal, yaitu adanya bukti-bukti bahwa terjadi kenaikan temperatur dengan penurunan kedalaman, yang besarnya sekitar ~25^oC per kilometer. Gradien geotermal berbeda-beda dari satu tempat ke tempat lainnya, tetapi indikasi yang diperlihatkan panas adalah berasal dari dalam bumi. Peristiwa ini kemungkinan akibat 2 proses:

Konduksi – adalah perpindahan panas melalui suatu benda padat. Contoh peristiwa ini adalah sendok yang tercelup sup di atas tungku atau kompor; atau telinga panci yang turut panas meskipun yang bersentuhan api hanya pada bagian dasarnya. Panasnya sendok atau “telinga” panci adalah keran proses konduksi

Konveksi – adalah perpindahan panas di dalam suatu material yang dipicu oleh perbedaan kondisi temperatur. Contoh peristiwa ini dapat diamati pada saat kita memanaskan air di dalam panci, suhu terpanas dari air di dalam panci adalah di bagian dasar, air panas ini naik dan air yang dingin di bagian atas akan turun untuk mengisi kekosongan yang ditinggalkan. Begitu terjadi berulang-ulang, sehingga air di panci terlihat mendidih atau bergolak .Aliran panas di permukaan bumi menunjukkan bahwa panas keluar dari dalam interior bumi secara konduksi melalui tubuh batuan yang padat. Desakan lelehan pijar batuan vulkanik pada gunungapi adalah contoh lain adanya arus konveksi dari dalam bumi. Arus konveksi ini terjadi pula di bagian atas interior bumi (mantle) dan memicu pergerakan kerak bumi yang dikenal sebagai pergerakan tektonik lempeng. Hal ini selanjutnya digunakan untuk menjelaskan bagaimana gunungapi terdistribusi atau di mana pusat-pusat gempa tersebar di belahan bumi (Yunus Ashari, Ir, MT).

Montauk Monster

noreply@blogger.com (Meenviro) — Sat, 16 Oct 2010 18:10:00 PDT

Montauk Monster:"Montauk Monster" was the unidentified creature which allegedly washed ashore, dead on a beach near the business district of Montauk, New York, in July 2008. being the identity and veracity of stories surrounding it have been the subject of unresolved disputes and speculation, although the current consensus, based on the dental models and details of the front paws, he was a raccoon.

The story began with a July 23, 2008 article in the local newspaper, The Independent. Main Britton, 20, of Bay Shore, and three friends said they found the creature on July 12 at Ditch Plains beach, two miles east of the district. Beach popular surfing spot at Rheinstein Estate Park owned by the city of East Hampton. Chief Britton quotes:

We are looking for a place to work, when we saw some people looking at something . We do not know what it was . We joked that maybe it was something from Plum Island.

Her color photograph ran in black and white under the headline "Dog Bonacville" (take-off on the name of the Bonackers, which belongs to the natives of East Hampton and the Hound of the Baskervilles is a book of Sherlock Holmes series by Sir Arthur Conan Doyle). Carefree article suggests that there may be a turtle or some mutant experiment from Plum Island Animal Disease Center before noting that Larry Penny, East Hampton Natural Resources Director, concluded it was a raccoon with its upper jaw missing. The article concluded that "someone took . to be buried . we hope." the local newspaper quoted an unidentified woman, who claimed that the animal was only the size of a cat, and was decomposed into a skeleton while press coverage. She would not identify its location for inspection. Father Hewitt denies claims that his daughter is to keep the secret places of the body. (http://www.usposttoday.com)

WTC collapse: Jesse Ventura on FOX Business News 10/14/10 in Heated 9/11 Discussion

noreply@blogger.com (Meenviro) — Sat, 16 Oct 2010 02:00:19 PDT

Former Minnesota Gov. Jesse Ventura, who during the Vietnam War was part of the Navy's Underwater Demolition Team, claims that

"I'm suggesting that governments do things to get us into wars," the former pro-wrestler told Eric Bolling on Fox Business News yesterday in an interview to promote Ventura's new cable TV show, "Conspiracy Theory," which premieres Friday. "I'm saying 9/11 was to get us into Iraq and get us into Afghanistan," the actor formerly known as The Body told Bolling on "Follow The Money".

When asked by Bolling if he really believed that the attacks on Sept. 11, 2001, specifically on the World Trade Center, happened so we could get oil from Iraq, the typically outspoken Ventura said "yes, and so we can have lithium from Afghanistan."

This isn't the first time Ventura has publicly expressed his theories about 9/11. As early as April 2008, the former governor appeared on the Alex Jones show and said that after his son insisted that he watch the 9/11 consipiracy theory documentary "Loose Change" he began to doubt the WTC collapse.

"When I finally did watch it I went through every emotion you could imagine, from laughing, crying, getting sick to my stomach, to the whole emotional thing," Ventura told Jones in 2008. (http://www.usposttoday.com)