Selasa, 07 Desember 2010

What is The Ozone Hole?

The ozone hole is not technically a “hole” where no ozone is present, but is actually a region of exceptionally depleted ozone in the stratosphere over the Antarctic that happens at the beginning of Southern Hemisphere spring (August–October). Satellite instruments provide us with daily images of ozone over the Antarctic region. The ozone hole image below shows the very low values (blue and purple colored area) centered over Antarctica on October 4, 2004. From the historical record we know that total column ozone values of less than 220 Dobson Units were not observed prior to 1979. 

What is Ozone?

Ozone is a form of elemental oxygen. In its most stable form, elemental oxygen exists as diatomic molecules (O2). Ozone is a gas made up of three oxygen atoms (O3). Ozone is a very reactive gas, and even at low concentrations it is irritating and toxic. It occurs naturally in small (trace) amounts in the upper atmosphere (the stratosphere). Ozone protects life on Earth from the Sun’s ultraviolet (UV) radiation. In the lower atmosphere (the troposphere) near the Earth’s surface, ozone is created by chemical reactions between air pollutants from vehicle exhaust, gasoline vapors, and other emissions. At ground level, high concentrations of ozone are toxic to people and plants.

What Chemicals do Reverse Osmosis Remove/Reduce?

Reverse osmosis will generally remove any molecular compounds smaller in size than water molecules. Such compounds include salt, manganese, iron, fluoride, lead, and calcium (Binnie et al, 2002). Reverse osmosis is extremely efficient at stripping minerals from water, and it is highly valued as a water purification process in the printing industry, in which mineral-free water must be used.

Pro and Contra of Reverse Osmosis Water

The semi-permeable membrane used in reverse osmosis contains tiny pores through which water can flow. The small pores of this membrane are restrictive to such organic compounds as salt and other natural minerals, which generally have a larger molecular composition than water. These pores are also restrictive to bacteria and disease-causing pathogens. Thus, reverse osmosis is incredibly effective at desalinating water and providing mineral-free water for use in photo or print shops. It is also effective at providing pathogen-free water. In areas not receiving municipally treated water or at particular risk of waterborne diseases, reverse osmosis is an ideal process of contaminant removal.


How does it work?
 Reverse osmosis was developed as a water treatment method more than 40 years ago. Reverse osmosis refers to a process of water purification that has been used primarily for the desalination of seawater. To understand reverse osmosis, it is first necessary to understand osmosis. Osmosis is the term for the phenomenon whereby if a semi-permeable membrane separates two salt solutions of different concentration, water will migrate from the weaker solution through the membrane to the stronger solution, until the solutions are of the same salt concentration. Reverse osmosis subverts this process. It involves applying pressure to reverse the natural flow of water, forcing the water to move from the more concentrated solution to the weaker. The semi-permeable membrane is porous, allowing water to pass through, but blocking the passage of the bulkier salt molecules (Binnie, Kimber, & Smethurst, 2002). The end result is water sans salt on one side of the membrane.

Minggu, 05 Desember 2010

What would happen if our atmosphere had something else instead of nitrogen?

Inert gases like helium and argon are used in place of nitrogen in scuba tanks. The nitrogen in the air is not available directly for the nitrogen cycle (what little is 'fixed' only make up only 5-8% of the nitrogen in the cycle), so its absence should not affect life that much. Nitrogen was still necessary in Earth's early atmosphere to form ammonia and amino acids, the basic building blocks of DNA and life, but there could have been less, or the nitrogen could have lost for some reason, or some reason why the atmosphere is deficient in nitrogen. Definitely life would still be possible if a large portion of the atmosphere were currently say argon and oxygen, not really much different than Earth life now. Too much CO2 could cause health problems or death to humans, even with 20% O2. Of course, with 80% CO2, the atmosphere would have an extreme greenhouse effect and would get like Venus and life could not exist.

Helium is very light, and most of it escaped from the early Earth, so a heavier, similar gas like argon, which makes up 1% of the atmosphere would be a more likely good candidate to replace nitrogen.
Dwi A (08-44)

What are people,government, and kid doing to stop global warming?

People are doing many things to try to stop global warming. One thing people are doing is carpooling. Carpooling is driving with someone to a place that you are both going to. This minimizes the amount of greenhouse gases put into the air by a car.
Another thing that people are doing is being more careful about leaving things turned on like the television, computer, and the lights. A lot of people are taking time away from the television, and instead, they are spending more time outdoors. This helps our planet out a lot. Now, more people are even riding busses, walking to school, and riding their bikes to lower the amount of greenhouse gases in the air. Planting trees and recycling also helps. If you recycle, less trash goes to the dump, and less trash gets burned. As a result, there are fewer greenhouse gasses in our atmosphere.
Watch what you buy. Many things, such as hairspray and deodorant, now are made to have less of an impact on the atmosphere. Less greenhouse gasses will rise into the air, and global warming will slow down.

The government is doing many things to help stop global warming. The government made a law called The Clean Air Act so there is less air pollution. Global warming is making people get very bad illnesses that could make them disabled, very sick, and sometimes even die. The Clean Air Act is making many companies change their products to decrease these problems. Part of the law says that you may not put a certain amount of pollutants in the air. Hairspray and some other products, like foam cups, had this problem. Making and using these products let out too much volatile organic compounds (VOC’s), ozone-destroying chemicals (chlorofluorocarbons (CFC’s), and related chemicals (such as CO2) into the air. Now, almost all of these products have a label on them telling people what this product can do to the environment and many people. By 2015 all products listed on the Clean Air Act will have this label on them:
Almost all of the other chemicals that could be harmful will have this label on them hopefully by this time (2015) as well.
The Clean Air Act has also made car companies change some of the things inside of the cars. Cars pollute a lot. While cars make more than half of the world’s smog (visible pollution in the air), many things that cars need to move and heat up make even more pollution. Some things that are inside of cars, buses, trucks, and motorcycles, like gasoline, pollute the air when the fuel is burned. It comes out as a chemical and when mixed in the air, forms smog. Smog is a kind of pollution that you see in the form of a cloud. If you have ever been to California you can see a lot of smog in some places. Sometimes the smog gets so bad that you cannot see at all! Smog forms when car exhaust, pollution from homes, and pollution from factories mixes in the air and has a chemical reaction. The sun’s heat and light add to the reaction.
Cars, buses, and trucks are also responsible for over 50% of dangerous chemicals let into the air. Some of these chemicals can cause cancer, birth defects, trouble breathing, brain and nerve damage, lung injures, and burning eyes. Some of the pollutants are so harmful that they can even cause death.

Although adults do many things to help stop global warming, kids can do just as much. Kids can’t do hard things like making a law, but we can do easier things like not watching as much TV. You can listen to your parents when they say, turn off your lights or go play outside. Listening to them and actually trying to help can help you, your environment, and the world.
Dwi A (08-44)


Global warming is when the earth heats up (the temperature rises).  It happens when greenhouse gases (carbon dioxide, water vapor, nitrous oxide, and methane) trap heat and light from the sun in the earth’s atmosphere, which increases the temperature.  This hurts many people, animals, and plants.  Many cannot take the change, so they die.

Global warming is affecting many parts of the world.  Global warming makes the sea rise, and when the sea rises, the water covers many low land islands.  This is a big problem for many of the plants, animals, and people on islands.  The water covers the plants and causes some of them to die.  When they die, the animals lose a source of food, along with their habitat.  Although animals have a better ability to adapt to what happens than plants do, they may die also.  When the plants and animals die, people lose two sources of food, plant food and animal food.  They may also lose their homes.  As a result, they would also have to leave the area or die.  This would be called a break in the food chain, or a chain reaction, one thing happening that leads to another and so on.  
The oceans are affected by global warming in other ways, as well.  Many things that are happening to the ocean are linked to global warming.  One thing that is happening is warm water, caused from global warming, is harming and killing algae in the ocean.
Algae is a producer that you can see floating on the top of the water.  (A producer is something that makes food for other animals through photosynthesis, like grass.)  This floating green algae is food to many consumers in the ocean.  (A consumer is something that eats the producers.)  One kind of a consumer is small fish.  There are many others like crabs, some whales, and many other animals.  Fewer algae is a problem because there is less food for us and many animals in the sea. 
Global warming is doing many things to people as well as animals and plants.  It is killing algae, but it is also destroying many huge forests.  The pollution that causes global warming is linked to acid rain.  Acid rain gradually destroys almost everything it touches.  Global warming is also causing many more fires that wipe out whole forests.  This happens because global warming can make the earth very hot.  In forests, some plants and trees leaves can be so dry that they catch on fire. 
Many things cause global warming.  One thing that causes global warming is electrical pollution.  Electricity causes pollution in many ways, some worse than others.  In most cases, fossil fuels are burned to create electricity.  Fossil fuels are made of dead plants and animals.  Some examples of fossil fuels are oil and petroleum.  Many pollutants (chemicals that pollute the air, water, and land) are sent into the air when fossil fuels are burned.  Some of these chemicals are called greenhouse gasses.
We use these sources of energy much more than the sources that give off less pollution.  Petroleum, one of the sources of energy, is used a lot.  It is used for transportation, making electricity, and making many other things.  Although this source of energy gives off a lot of pollution, it is used for 38% of the United States’ energy.
Some other examples of using energy and polluting the air are:

urning on a light

Watching T.V.

Listening to a stereo
Washing or drying clothes

Using a hair dryer

Riding in a car

Heating a meal in the microwave

Using an air conditioner

Playing a video game

Using a dish washer
When you do these things, you are causing more greenhouse gasses to be sent into the air.  Greenhouse gasses are sent into the air because creating the electricity you use to do these things causes pollution.  If you think of how many times a day you do these things, it’s a lot.  You even have to add in how many other people do these things!  That turns out to be a lot of pollutants going into the air a day because of people like us using electricity. The least amount of electricity you use, the better.
When we throw our garbage away, the garbage goes to landfills.  Landfills are those big hills that you go by on an expressway that stink.  They are full of garbage.  The garbage is then sometimes burned.  This sends an enormous amount of greenhouse gasses into the air and makes global warming worse.
Another thing that makes global warming worse is when people cut down trees.  Trees and other plants collect carbon dioxide (CO2), which is a greenhouse gas.
Carbon dioxide is the air that our body lets out when we breathe. With fewer trees, it is harder for people to breathe because there is more CO2 in the air, and we don’t breathe CO2, we breathe oxygen.  Plants collect the CO2 that we breathe out, and they give back oxygen that we breathe in.  With less trees and other plants, such as algae, there is less air for us, and more greenhouse gases are sent into the air. This means that it is very important to protect our trees to stop the greenhouse effect, and also so we can breathe and live. 
This gas, CO2, collects light and heat (radiant energy), produced by the sun, and this makes the earth warmer.  The heat and light from the sun is produced in the center of the sun.  (The sun has layers just like the earth.) 

This layer is called the core.  Just like a core of an apple, it is in the middle.  Here there is a very high temperature, about 27,000,000°F.  This heat escapes out of this layer to the next layer, the radiative zone. This layer is cooler, about 4,500,000°F.   Gradually, the heat and light will pass through the convection zone at a temperature of around 2,000,000°F.  When it gets to the surface, the temperature is about 10,000°F.  Finally, the heat and light is sent into space.  This is called radiant energy (heat and light).  The radiant energy reaches the earth’s atmosphere.  As a result of this process we get light and heat.  When you pollute, you send chemicals into the air that destroy our atmosphere, so more heat and light cannot escape from the earth’s atmosphere.
Some other chemicals that cause air pollution and are bad for the environment and people are:

Ozone- Ozone is produced when other pollution chemicals combine.  It is the basic element of smog.  It causes many different kinds of health issues dealing with the lungs.  It can damage plants and limit sight.  It can also cause a lot of property damage.

VOC’s (volatile organic compounds, smog formers)- VOC’s are let into the air when fuel is burned. This chemical can cause cancer.  It can also harm plants.

NOx (nitrogen dioxide)- This chemical forms smog.  It is also formed by burning sources of energy, like gas, coal, and oil, and by cars.  This chemical causes problems in the respiratory system (including the lungs).  It causes acid rain, and it can damage trees.  This chemical can eat away buildings and statues.

CO (carbon monoxide)- The source of this chemical is burning sources of energy.  It causes blood vessel problems and respiratory failures.

PM-10 (particulate matter)- The source of this chemical is plowing and burning down fields.  It can cause death and lung damage.  It can make it hard for people to breathe.  The smoke, soot, ash, and dust formed by this chemical can make many cities dirty.

Sulfur Dioxide- This chemical is produced by making paper and metals.  This chemical can cause permanent lung damage.  It can cause acid rain which kills trees and damages building and statues.

Lead- This chemical is in paint, leaded gasoline, smelters, and in lead storage batteries.  It can cause many brain and nerve damages and digestive problems.
  DWI A (08-44)

Layers of the Earth's Atmosphere (Part 2)

The Troposphere

The troposphere is the lowest layer of the Earth's atmosphere. The air is very well mixed and the temperature decreases with altitude.
Air in the troposphere is heated from the ground up. The surface of the Earth absorbs energy and heats up faster than the air does. The heat is spread through the troposphere because the air is slightly unstable.
Weather occurs in the Earth's troposphere.

The Stratosphere

In the Earth's stratosphere, the temperature increases with altitude. On Earth, ozone causes the increasing temperature in the stratosphere. Ozone is concentrated around an altitude of 25 kilometers. The ozone molecules absorb dangerous kinds of sunlight, which heats the air around them.
The stratosphere is located above the top of the the troposphere.

Ozone - An Overview

The Ozone Hole. Pollution. Skin Cancer. Why does the topic of ozone make the news so much? How important is the ozone in our atmosphere? Why are scientists so concerned about its increase near the surface of the Earth and its disappearance higher up in the atmosphere?
First things first - what is ozone? Ozone is made of three oxygen atoms (O3). The oxygen in our atmosphere that we breathe is made up of two oxygen atoms (O2). When enough ozone molecules are present, it forms a pale blue gas. Ozone has the same chemical structure whether it is found in the stratosphere or the troposphere. Where we find ozone in the atmosphere determines whether we consider it to be "good" or "bad"!
In the troposphere, the ground-level or "bad" ozone is an air pollutant that damages human health, vegetation, and many common materials. It is a key ingredient of urban smog. In the stratosphere, we find the "good" ozone that protects life on Earth from the harmful effects of the Sun's ultraviolet rays. We have good reason to be concerned about the thinning of the ozone layer in the stratosphere. We also have good reason to be concerned about the buildup of ozone in the troposphere. Although simplistic, the saying "Good up high and bad near by," sums up ozone in the atmosphere.

Ozone in the Stratosphere

About 90% of the ozone in the Earth's atmosphere is found in the region called the stratosphere. This is the atmospheric layer between 16 and 48 kilometers (10 and 30 miles) above the Earth's surface. Ozone forms a kind of layer in the stratosphere, where it is more concentrated than anywhere else.
Ozone and oxygen molecules in the stratosphere absorb ultraviolet light from the Sun, providing a shield that prevents this radiation from passing to the Earth's surface. While both oxygen and ozone together absorb 95 to 99.9% of the Sun's ultraviolet radiation, only ozone effectively absorbs the most energetic ultraviolet light, known as UV-C and UV-B. This ultraviolet light can cause biological damage like skin cancer, tissue damage to eyes and plant tissue damage. The protective role of the ozone layer in the upper atmosphere is so vital that scientists believe life on land probably would not have evolved - and could not exist today - without it.
The ozone layer would be quite good at its job of protecting Earth from too much ultraviolet radiation - that is, it would if humans did not contribute to the process. It's now known that ozone is destroyed in the stratosphere and that some human-released chemicals such as CFC’s are speeding up the breakdown of ozone, so that there are "holes" now in our protective shield.
While the stratospheric ozone issue is a serious one, in many ways it can be thought of as an environmental success story. Scientists detected the developing problem, and collected the evidence that convinced governments around the world to take action. Although the elimination of ozone-depleting chemicals from the atmosphere will take decades yet, we have made a strong and positive beginning. For the first time in our species' history, we have tackled a global environmental issue on a global scale.

The Mesosphere

In the Earth's mesosphere, the air is relatively mixed together and the temperature decreases with altitude. The atmosphere reaches its coldest temperature of around -90°C in the mesosphere. This is also the layer in which a lot of meteors burn up while entering the Earth's atmosphere.
The mesosphere is on top of the stratosphere The upper parts of the atmosphere, such as the mesosphere, can sometimes be seen by looking at the very edge of a planet.

The Thermosphere

The thermosphere is the fourth layer of the Earth's atmosphere and is located above the mesosphere. The air is really thin in the thermosphere. A small change in energy can cause a large change in temperature. That's why the temperature is very sensitive to solar activity. When the sun is active, the thermosphere can heat up to 1,500° C or higher!
The Earth's thermosphere also includes the region of the atmosphere called the ionosphere. The ionosphere is a region of the atmosphere that is filled with charged particles. The high temperatures in the thermosphere can cause molecules to ionize. This is why an ionosphere and thermosphere can overlap.

The Ionosphere

Scientists call the ionosphere an extension of the thermosphere. So technically, the ionosphere is not another atmospheric layer. The ionosphere represents less than 0.1% of the total mass of the Earth's atmosphere. Even though it is such a small part, it is extremely important!
The upper atmosphere is ionized by solar radiation. That means the Sun's energy is so strong at this level, that it breaks apart molecules. So there ends up being electrons floating around and molecules which have lost or gained electrons. When the Sun is active, more and more ionization happens!
Different regions of the ionosphere make long distance radio communication possible by reflecting the radio waves back to Earth. It is also home to auroras.
Temperatures in the ionosphere just keep getting hotter as you go up!

Regions of the Ionosphere

The ionosphere is broken down into the D, E and F regions. The breakdown is based on what wavelength of solar radiation is absorbed in that region most frequently.
The D region is the lowest in altitude, though it absorbs the most energetic radiation, hard x-rays. The D region doesn't have a definite starting and stopping point, but includes the ionization that occurs below about 90km.
The E region peaks at about 105km. It absorbs soft x-rays.
The F region starts around 105km and has a maximum around 600km. It is the highest of all of the regions. Extreme ultra-violet radiation (EUV) is absorbed there.
On a more practical note, the D and E regions reflect AM radio waves back to Earth. Radio waves with shorter lengths are reflected by the F region. Visible light, television and FM wavelengths are all too short to be reflected by the ionosphere. So your t.v. stations are made possible by satellite transmissions.

The Sun's Effect on the Ionosphere

Invisible layers of ions and electrons are found in the Earth's atmosphere. We call this region of atmosphere the ionosphere.
The main source of these layers is the Sun's ultraviolet light which ionizes atoms and molecules in the Earth's upper atmosphere. During this process, electrons are knocked free from molecules or particles in the atmosphere.
Flares and other big events on the Sun produce increased ultraviolet, x-ray and gamma-ray photons that arrive at the Earth just 8 minutes later (other particles from the Sun may arrive days later) and dramatically increase the ionization that happens in the atmosphere. So, the more active the Sun, the thicker the ionosphere!

The Exosphere

Very high up, the Earth's atmosphere becomes very thin. The region where atoms and molecules escape into space is referred to as the exosphere. The exosphere is on top of the thermosphere.
 Dwi A(08_44)

Layers of Earth's Atmosphere (part 1)

The Earth's Atmosphere

The atmosphere surrounds Earth and protects us by blocking out dangerous rays from the sun. The atmosphere is a mixture of gases that becomes thinner until it gradually reaches space. It is composed of Nitrogen (78%), Oxygen (21%), and other gases (1%).

Oxygen is essential to life because it allows us to breathe. Some of the oxygen has changed over time to ozone. The the ozone layer filters out the sun's harmful rays. Recently, there have been many studies on how humans have caused a hole in the ozone layer.

Humans are also affecting Earth's atmosphere through the greenhouse effect. Due to increases in gases, like carbon dioxide, that trap heat being radiated from the Earth, scientists believe that the atmosphere is having trouble staying in balance creating the greenhouse effect .

The atmosphere is divided into five layers depending on how temperature changes with height. Most of the weather occurs in the first layer.
Layers of the Earth's Atmosphere

The atmosphere is divided into five layers. It is thickest near the surface and thins out with height until it eventually merges with space.

1. The troposphere is the first layer above the surface and contains half of the Earth's atmosphere. Weather occurs in this layer.
2. Many jet aircrafts fly in the stratosphere because it is very stable. Also, the ozone layer absorbs harmful rays from the Sun.
3. Meteors or rock fragments burn up in the mesosphere.
4. The thermosphere is a layer with auroras. It is also where the space shuttle orbits.
5. The atmosphere merges into space in the extremely thin exosphere. This is the upper limit of our atmosphere.
 Dwi A(08-44)

Ruas Muntilan-Yogyakarta Ditutup Karena Banjir Lahar Dingin

Banjir lahar dingin susulan yang melewati sejumlah sungai mengakibatkan jalur Jalan Raya Muntilan Kabupaten Magelang-Yogyakarta ditutup, karena air dan material Gunung Merapi meluap hingga badan jalan, Ahad

"Sejak sekitar pukul 12.30 WIB hingga saat ini (sekitar pukul 14.00 WIB) jalan Magelang-Yogyakarta ditutup," kata Kepala Sub Bidang Penanggulangan Bencana, Badan Kesatuan Bangsa, Politik, Perlindungan Masyarakat, dan Penanggulangan Bencana Pemerintah Kabupaten Magelang, Jawa Tengah, Heri Prawoto di Magelang.

Luapan air dan pasir Merapi, katanya, hingga di atas Jembatan Gempol, Dusun Gulon, Kecamatan Salam, Kabupaten Magelang di aliran Kali Putih, dan Jembatan Muntilan, Kecamatan Muntilan, di aliran Kali Blongkeng.

Ia menjelaskan, penutupan arus lalu lintas untuk mengantisipasi jatuhnya korban. "Hingga saat ini tidak ada korban akibat banjir lahar dingin susulan, dampak sekunder letusan Gunung Merapi," ucapnya.

Pemakai jalur setempat dialihkan ke jalan lain yang relatif aman dari bahaya banjir lahar dingin susulan. Antrean berbagai jenis kendaraan terjadi hingga kawasan Taman Agung, Muntilan, sedangkan Jalan Pemuda di pusat kota Kecamatan Muntilan yang hari biasa hanya untuk satu jalur, digunakan untuk dua jalur.

Kemungkinan, katanya, hujan cukup deras terjadi di kawasan Gunung Merapi. Petugas pengamatan Gunung Merapi di Pos Krinjing, Kecamatan Dukun, Kabupaten Magelang, Yulianto mengatakan, hujan cukup deras di kawasan lereng barat puncak Merapi sejak sekitar pukul 11.30 hingga 13.00 WIB.

"Sedangkan di sisi barat laut dan utara hanya gerimis, memang terjadi peningkatan volume air antara lain di alur Sungai Apu, Trising, dan Senowo. Kali Lamat juga banjir lahar dingin," paparnya.
Dwi A(08-44)

Banjir Lahar Dingin Menyebabkan Jembatan Landon Putus

Jembatan Landon yang berada di Dukuh Sepi, Desa Jrakah, Kecamatan Selo, Boyolali, Jawa Tengah, Jembatan Ladon, putus usai diterjang lahar dingin. Jembatan itu berada di atas sungai yang berhulu dari puncak Gunung Merapi. Jembatan kini hancur dan ada beberapa batu berukuran raksasa menutupi jalan yang ada.

Akibat banjir lahar dingin juga membuat akses jalan menuju dua kampung di Desa Klakah, Kecamatan Selo, Boyolali, Jateng, terputus. Dua kampung yang terisolasi adalah Kampung Bakalan dan Sumber yang jumlah warganya sekitar seribu jiwa.

Alhasil, warga setempat harus turun ke jurang sungai dengan berjalan atau mengendarai sepeda motor dengan cara ekstra hati-hati untuk bisa menyeberang. Sedangkan untuk kendaraan roda empat, sama sekali tidak bisa melalui jembatan tersebut. Padahal Jembatan Ladon adalah jalur satu-satunya menuju Kampung Bakalan dan Sumber.

Warga berharap pemerintah setempat segera membangun jembatan baru yang lebih kokoh. Dengan begitu akses jalan warga bisa kembali normal.
Dwi A(08-44)

Bigger eruptions at Mt. Bromo

Mount Bromo could be on the brink of bigger eruptions, an official from the Volcanology and Geological Disaster Mitigation Center said,

Mohamad Syafii, who is also the head of the Mt. Bromo observation post at Ngadisari, Sukapura district in Probolinggo, based his prediction on changes in the eruption characteristics over the last few years.

He said that before, eruptions had longer intervals and were smaller in scale, whereas now, the period between eruptions was much shorter and the eruptions themselves more intense.

“Bromo continues to spew ash, which it has done for the last seven days. It looks likely that there is still a lot of energy built up,” Syafii said.

He compared the energy build up of the recent eruptions to the earlier eruptions on June 8, 2004, and

“In 2004, Mt. Bromo discharged volcanic material briefly — only within 20 minutes. After that it ran out of steam,” Syafii said.

He said he did not know when a major eruption would take place as the energy could still be discharged through smaller eruptions.
Dwi A(08-44)