Exploding Lakes - Horrifying Natural Phenomena




Exploding lakes are a terrible natural phenomena and very serious environmental problem.

These lakes are capable of killing thousands, even millions of people and animals living in the region.

In 1986 an awful tragedy occurred when Lake Nyos, in the volcanic region of Cameroon, suddenly released a cloud of carbon dioxide into the atmosphere, killing 1,700 people and 3,500 livestock in nearby towns and villages.

Scientists were at the time not aware of the exploding lake phenomenon although the first event happened in 1984, when 37 people near Lake Monoun died suddenly.

Lake Nyos is an active crater lake that formed by an eruption about 5 centuries ago.

Nyos is located about 95 km from Lake Monoum. Together these two are the only two volcanic lakes in the world other than Lake Kivu that contain large amounts of CO2.


After many years of study the science community has come to an agreement that the origin of CO2 within Lake Nyos is due to CO2 that rises from volcanic activity.
This CO2 is then dissolved into groundwaters and transferred to the lake resulting in the slow saturation of the hypolimnion.

Cameroon's exploding lakes are a unique example of this phenomenon, where CO2 is trapped in the bottom water of deep volcanic craters.

The gas stays at the bottom of the lake, held down by the pressure of the overlying water.

But eventually, CO2 gas can start to bubble up to the top of the lake, which reduces the water pressure that usually holds the gas down.

        Lake Nyos was responsible for the death of 1,700 people and 3,500 livestock

When this happens, the gas from the bottom of the lake can vent with exploding force, creating a suffocating cloud that can kill people and animals in low-lying areas.

In order to prevent Lake Nyos from exploding again, an international team of scientists and engineers has developed and implemented a program to artificially remove gas from the lake through piping.

USGS scientists initially advised on the project and have long monitored gas levels in the lake to determine whether this removal has been successful. They'll also update devices monitoring gas levels in nearby Lake Monoun, another exploding lake, where CO2 has now been completely removed as part of the same project.

In 2001, a French engineering firm installed pipes that reached the very bottom of the lakes. Pumps initially push some of the lower water upward, releasing water pressure and allowing CO2 gas bubbles to form. Once bubbles form, the gas naturally flows up and out of the pipe at a controlled rate.

This technique has successfully resulted in the complete degassing of Cameroon's Lake Monoun, which now poses no risk of gas release. Much of the gas in Lake Nyos has been removed as well, but degassing will continue for several more years before the CO2 is completely gone.

                                                        Lake Kivu

The USGS continues to monitor water conditions at these two lakes. The probes that measure the dissolved gas pressure are built at USGS, and are permanently installed in the lakes. After a decade of use, the most recent probes now need to be replaced.

Unfortunately, this problem is not yet solved. According to recent reports, the lake now contains twice as much carbon dioxide as was released during the explosion. Earlier attempts to siphon off the gas had to be abandoned for financial reasons.

If Lake Kivu were to explode, over two million people and thousands of animals who live around it would be in danger.

Can we really say we lack financial resources to prevent these defenseless living beings from a possible horrifying death?







Print Page

Arctic sea ice melt 'may bring harsh winter to Europe'



The unprecedented loss of polar sea ice may lead to 'wild extremes' in the UK and northern Europe, say researchers

The record loss of Arctic sea ice this summer may mean a cold winter for the UK and northern Europe. The region has been prone to bad winters after summers with very low sea ice, such as 2011 and 2007, said Jennifer Francis, a researcher at Rutgers University.


"We can't make predictions yet … [but] I wouldn't be surprised to see wild extremes this winter," Francis told the Guardian.



This year's ice melt has broken the 2007 record by an an area larger than the state of Texas.

Polar ice experts "thought that it would be many years until we again saw anything like we saw in 2007", said Mark Serreze, director of the  National Snow and Ice Data Centre in Colorado.

The unprecedented expanse of ice-free Arctic Ocean has been absorbing the 24-hour sun over the short polar summer. The heat in the water must be released into the atmosphere if the ice is to re-form this autumn. "This is like a new energy source for the atmosphere," said Francis.


This heat and water vapour will affect the all-important jet stream – the west-to-east winds that are the boundary between cold Arctic and the warm mid-latitudes. Others researchers have already shown that the jet stream has been shifting northwards in recent years. Francis and colleagues have recently documented that the jet stream is also slowing down.

"The jet stream is clearly weaker," said Francis. That means weather systems, be it rain or dry conditions, are slow to move on and last longer. Ultimately this can result in "blocking" events, such as the conditions that produced the terrible heatwave in western Russia during the summer of 2010, she said.

This year’s record sea-ice melt might foreshadow a harsh winter in parts of Europe and North America. Recent research, although preliminary, suggests a connection between late-summer Arctic sea-ice extent and the location of areas of high and low atmospheric pressure over the northern Atlantic. The highs and lows can remain relatively fixed for weeks, shaping storm tracks and seasonal weather patterns such as extended cold surges.

Ralf Jaiser, a climate scientist at the Alfred Wegener Institute for Polar and Marine Research in Potsdam, Germany, found a significant correlation in 1989–2011 meteorological data between late-summer Arctic sea-ice extent and atmospheric-pressure anomalies that favour extreme weather such as prolonged cold snaps in winter. He reasons that in autumn, the open Arctic Ocean sheds heat to the high-latitude atmosphere. The warming tends to reduce the large-scale atmospheric-pressure gradient and weakens the dominant westerly winds in the Northern Hemisphere. Those winds normally sweep warm, moist Atlantic air to western Europe; their weakening leaves the region more prone to persistent cold.


“The impacts will become more apparent in autumn, once the freeze-up is under way and we see how circulation patterns have influenced the geographical distribution of sea ice,” says Judith Curry, a climate researcher at the Georgia Institute of Technology in Atlanta. But, she adds, “We can probably expect somewhere in the mid/high latitudes of the Northern Hemisphere to have a snowy and cold winter.”


   Ocean organisms are already seeing an impact

Arctic biology is already changing, as the retreat and thinning of sea ice allows more sunlight to penetrate the upper ocean and deprives certain species of habitat, says Jørgen Berge, a marine biologist at the University of Tromsø in Norway. For example, the dominant Arctic zooplankton — the copepods Calanus hyperboreus and C. glacialis — are being replaced by Atlantic C. finmarchicus. Meanwhile, Arctic cod (Arctogadus glacialis) is increasingly being out-competed by its larger Atlantic cousin Gadus morhua.


   There’s an important point that bears repeating: This is happening faster than we expected

Computer models that simulate how the ice will respond to a warming climate project that the Arctic will be seasonally ‘ice free’ (definitions of this vary) some time between 2040 and the end of the century. But the observed downward trend in sea-ice cover suggests that summer sea ice could disappear completely as early as 2030, something that none of the models used for the next report by the Intergovernmental Panel on Climate Change comes close to forecasting.



These changes are happening much earlier than scientists thought, said James Overland, an oceanographer and researcher at the University of Washington.

"We've only had a little bit of global warming so far," Overland said.

As the sea ice continues to decline, the jet stream will likely continue to slow more, and shift further north "bringing wild temperature swings and greater numbers of extreme events" in the future he said. "We're in uncharted territory."








Print Page
Related Posts Plugin for WordPress, Blogger...