The Dead Sea is a giant, super-saline lake at the lowest spot on Earth. And its beaches appear to be pebbled with perfect little cubes of salt. Crystal solids with flat sides like salt are symmetrical in shape because their molecules are arranged in a repeating pattern of positive and negative ions; the bonds between these electrons and protons are formed from electrostatic forces. Salt crystals are always cube-shaped, though impurities can cause crystals to grow into jagged chunks. Check out the Dead Sea salt cubes in this video:
The legendary sea links Israel and Jordan, though its shoreline has been moving ever since the sea’s been shrinking. People have been drawing large amounts of water from the rivers that feed it, and as the lake recedes, it leaves behind massive stores of solid salt in underground cavities. And when fresh water aquifers diffuse into those salt deposits, they create sinkholes -- at least a thousand of them have been found. Some scientists say the Dead Sea will be a puddle by 2055.
[Via Reddit]
The legendary sea links Israel and Jordan, though its shoreline has been moving ever since the sea’s been shrinking. People have been drawing large amounts of water from the rivers that feed it, and as the lake recedes, it leaves behind massive stores of solid salt in underground cavities. And when fresh water aquifers diffuse into those salt deposits, they create sinkholes -- at least a thousand of them have been found. Some scientists say the Dead Sea will be a puddle by 2055.
The lowest spot on Earth is gaining a teeny bit of altitude. Water level in the Dead Sea, whose shores lie about 423 meters below sea level, has been dropping for decades—not due to climate change, but because humans increasingly draw large amounts of water from the rivers that feed into the super-saline lake.
Data from buoys suggest that between 1993 and 2001, water level in the lake dropped an average of 88 centimeters each year.
But satellite data gathered during the same period, reported this month in the Journal of Geophysical Research-Solid Earth, indicate that the terrain within a few dozen kilometers of the Dead Sea rose as much as 4.3 millimeters per year, with the largest increases taking place along the lake's shore.
The slight rise in landscape stems directly from the decline in lake level, the scientists explain. Less water in the 67-kilometer-long lake means less weight pressing down on the surrounding terrain, so Earth's crust has rebounded upward—a faster, smaller-scale version of what happened when massive ice sheets melted at the end of the last ice age.
No comments :
Post a Comment