Ancient Conditions Around the Dead Sea Could Signal a Drier Future
The Dead Sea is losing about a meter of water each year.
The sea is on the border of Israel and Jordan. It is the lowest place on Earth meaning its surface is farther below sea level than any other place. And the sea's surface is getting lower because of below average rainfall in the area.
Now, an international team of geologists is seeking to understand how climate changes, over 200,000 years, have affected the area. They also may have found that a severe drought deeply changed the Dead Sea thousands of years ago.
The scientists have been studying soil sediment that shows dry seasons and wet seasons over thousands of years.
Marwan al-Raggad studies hydrology, or how water moves on the Earth. He is a member of a team studying the Dead Sea area. He said the group is looking at rocks and soil to find evidence of the climate in the area thousands of years ago. He said he is trying to develop a clear idea of the current conditions in order to "forecast the future climate of the Dead Sea area."
Recently, the team gathered samples from the eastern shore of the Dead Sea and from rivers and streams that flow into it.
Yael Kiro is a geochemist with the Lamont-Doherty Earth Observatory in New York City. She says her group is seeking a better understanding of the area's climate.
"We want to learn what's going on in the Dead Sea in terms of how much water is coming from the eastern side and what is the composition of water and what is the composition of sediments. We can't understand without this, the changes that we see in the Dead Sea and therefore we can't understand the climate without knowing what is going on here."
Members of the group said they are finding evidence of a huge drought thousands of years ago. The lack of rains was so severe that it dried up 80 percent of what today is a very salty lake.
Stephen Goldstein also is with the Lamont-Doherty Earth Observatory. He said understanding the past can help plan for the future.
"What happened in the past tells us something about what's possible in the future. And what happened in the past in this area is that the water that people are using now and need now stopped running."
Scientists with the observatory say that the area may have faced two periods of extremely dry conditions. One was 120,000 years ago, the other as recent as 10,000 years ago. During those periods, rainfall dropped to one fifth of its current level. The area is already considered arid, or very dry.
Kiro and Goldstein were among the authors of a study that provided evidence of past periods of extreme drought in the Dead Sea. The study was published in Earth and Planetary Science Letters.
The authors said their findings could be important as current climate models predict that the area may be in another historic dry period.
I'm Mario Ritter.
1.The Dead Sea 死海
Ancient scrolls were found in caves by the Dead Sea.
2.sea level 海平面
The melting ice caused a rise in sea level.
3.dried up 干枯的
The writer's imagination seems to have dried up.
4.flow into 流入
Two tributaries converge and flow into the river.
1."We want to learn what's going on in the Dead Sea in terms of how much water is coming from the eastern side and what is the composition of water and what is the composition of sediments.
in terms of 依据；按照
Taking a long view of the project, I began to think in terms of the rehearsal schedules required.
There is a substantial payback in terms of employee and union relations.
2.Now, an international team of geologists is seeking to understand how climate changes, over 200,000 years, have affected the area.
seek to 寻求；想办法
In order to maximize profit the firm would seek to maximize output.
He also denied that he would seek to annex the country.
死海位于以色列和约旦的边境 。它是地球海拔最低的地方，意味着死海的湖面比其他任何地方都要低 。由于当地的降水量低于平均值，死海的湖面逐渐降低 。
最近，由地质学家组成的国际团队正在探索，在过去的20万年里，气候变化是如何改变该地区的 。他们可能发现了，几千年前的一场严重干旱从很大程度上改变了死海 。
马文·奥拉格（Marwan al-Raggad）主要研究水文学，即地表径流 。他也是死海区域研究小组的一员 。他表示，团队正在观察岩石和土壤，来寻找千年前该地气候变化的证据 。为了“预测死海未来的气候状况”，他正努力梳理当前气象条件的理论 。
耶尔·基罗（Yael Kiro）是纽约拉蒙特-多尔蒂地球观测站的地质化学家 。她表示，小组的成员正在加深对该地区气候的了解 。
小组成员表示，他们正在搜罗千年前的一场严重干旱的证据 。当时降水量极少，死海蒸发掉了80%的水分，变成了如今的咸水湖 。
史蒂芬·戈德斯坦（Stephen Goldstein）也是拉蒙特-多尔蒂地球观测站的一员 。他表示，了解过去可筹划未来 。
“过去发生的一切可以告知未来可能发生的事 。该地区过去发生的事就是人们如今使用和需要的水枯竭了 。”
观测站的科学家表示，当地可能经历过两次极端干旱 。一次是在12万年前，另一次是在1万年前 。在这两个时期内，降水量下降到如今水量的五分之一 。该地区几近荒芜，寸草不生 。
基罗和戈德斯坦为死海过去的极端干旱时期提供了研究论据 。这项研究发表在《地球与行星科学快报》上 。