Ocean relentlessly, coastal areas will be flooded - VIDEO PDF Print E-mail
Saturday, 29 August 2015 15:41
On Wednesday, August 26, 2015 space agency NASA held a conference call with reporters. Experts told about the current projections of sea-level rise. The expert group of the newly formed teams studying the changes in sea level (Sea Level Change Team) argues that Ocean relentlessly, coastal areas will be flooded, but the speed of these changes is still unknown. "People need to be prepared for major changes and flooding of many coastal areas as sea-level rise is inevitable. The only question is how fast will take place, these processes," - said co-author Joshua Willis (Joshua Willis) climate scientist from the Laboratory of NASA's Jet Propulsion . At the conference, scientists said that the increase in the level of the oceans depends on three main determining factors. The first - the so-called thermal expansion, in which sea water expands when heated, which is why it takes a larger volume of sea level and, consequently, increases. This effect is further exacerbated by emissions of greenhouse gases by which the ocean receives more than 90% of the heat. The second important factor - the melting of glaciers in Greenland and Antarctica. The third reason - the melting of mountain glaciers. Ice sheets and glaciers may be lost forever because of the contact with the warm air, forming icebergs or in contact with warm seawater. It is believed that only the Greenland ice sheet was losing 303 gigatonnes of its mass every year for the past ten years (although this is not all scientists agree). This is the conclusion the researchers came as a result of observation by means of special satellites NASA. According to experts, precise data were provided by satellites Jason 1 and 2 Jason and TOPEX / Poseidon. Altimeters of observation stations allowed a record accurate measurements. At the same time the satellite GRACE measured the Earth's gravitational field and determine how the mass of glaciers and ice sheets of the polar regions of our planet. As it turned out, since the early 20th century, sea levels rose by 20.3 centimeters. Further calculations on models have shown that the end of the 21 th century the sea level could rise by another 90 centimeters. Nevertheless, it is important to bear in mind that these figures give an average rating of the world, whereas in some areas of the Earth's sea level has grown much stronger, while others do not just increased, but even fell. "The level of the coastal waters of the west coast of the United States actually fell over the past 20 years. This is because of global warming are the long-term natural cycles. However, there are signs and the fact that the current picture is changing. Over the next decade can be expected to accelerate the pace of sea-level rise along the west coast of the US, as the region recovers from the temporary lowering of the Ocean "- says Willis. Most concern to scientists is East Antarctica, melting glaciers that flows under the "waterline" (that is below sea level). This means that trace the changes in the ice sheets of the polar continent part of the space is not possible in this case to rely on indirect methods to assess the situation. To improve the understanding of the climatic situation, experts NASA launched a six-year program called Oceans Melting Greenland, which will aim to study the influence of warm ocean water on Greenland's glaciers. By combining satellite imagery with ground observations, NASA scientists hope to give a more accurate predictions about rising sea levels.