Category Archives: Geology

Ancient DNA Found Hidden Below Sea Floor

Posted on by
Reply

Minute fossil sea creatures recovered from sediments containing ancient DNA. Image: Lejzerowicz et al./Biology Letters

In the middle of the South Atlantic, there’s a patch of sea almost devoid of life. There are no birds, few fish, not even much plankton. But researchers report that they’ve found buried treasure under the empty waters: ancient DNA hidden in the muck of the sea floor, which lies 5000 meters below the waves.

The DNA, from tiny, one-celled sea creatures that lived up to 32,500 years ago, is the first to be recovered from the abyssal plains, the deep-sea bottoms that cover huge stretches of Earth. In a separate finding published this week, another research team reports teasing out plankton DNA that’s up to 11,400 years old from the floor of the much shallower Black Sea. The researchers say that the ability to retrieve such old DNA from such large stretches of the planet’s surface could help reveal everything from ancient climate to the evolutionary ecology of the seas. Read more

 

Supervolcano Mount Toba Didn’t Cause Humans’ Near-Extinction

Posted on by
Reply
Mount Toba on the Indonesian island of Sumatra

Mount Toba on the Indonesian island of Sumatra

A supervolcanic eruption thought to have nearly driven humanity extinct may not have endangered the species after all, a new investigation suggests.

Supervolcanoes are capable of eruptions dwarfing anything ever seen in recorded history, expelling thousands of times more magma and ash than even a Mount St. Helens or Pinatubo. A supervolcanic eruption could wreak as much havoc as the impact of a mile-wide asteroid,by blotting out the sun with ash, reflecting its rays and cooling the Earth — a phenomenon called a “volcanic winter.” A dozen or so supervolcanoes exist today, some of them lying at the bottom of the sea. Read more

 

Yellowstone’s Volcano Bigger Than Thought

Posted on by
Reply

Geologists believe Yellowstone sits over a hotspot, a plume of superheated rock rising from Earth’s mantle

Yellowstone’s underground volcanic plumbing is bigger and better connected than scientists thought, geologists reported this week at the Seismological Society of America’s annual meeting.

“We are getting a much better understanding of the volcanic system of Yellowstone,” said Jamie Farrell, a c graduate student at the University of Utah. “The magma reservoir is at least 50 percent larger than previously imaged.” Read more

 

Did an Earthquake Destroy Ancient Greece?

Posted on by
Reply

Remnants of Cyclopean walls built by the Mycenaeans can be found at the Acropolis in Athens, Greece. ISTOCKPHOTO

The grand Mycenaens, the first Greeks, inspired the legends of the Trojan Wars, “The Iliad” and “The Odyssey.” Their culture abruptly declined around 1200 B.C., marking the start of a Dark Ages in Greece.

The disappearance of the Mycenaens is a Mediterranean mystery. Leading explanations include warfare with invaders or uprising by lower classes. Some scientists also think one of the country’s frequent earthquakes could have contributed to the culture’s collapse. At the ruins of Tiryns, a fortified palace, geologists hope to find evidence to confirm whether an earthquake was a likely culprit. Read more

 

Long-Lost Continent Of ‘Mauritia’ Buried Beneath Indian Ocean

Posted on by
Reply

The beaches of Mauritius contain fragments of a type of rock typical of ancient continental crust — rock which could have been brought to the surface by volcanic eruptions. JACK ABUIN/ZUMA PRESS/CORBIS

A a group of international scientists have found evidence that an ancient, lost continent may be buried beneath the Indian Ocean floor.

Nature reports that the study, published Feb. 24 in the journal Nature Geoscience, reports that fragments of an ancient micro-continent dubbed “Mauritia” now lie underwater between Madagascar and India.

As evidence of this lost continent, the researchers point to ancient sand grains that contain minerals pre-dating the volcanic eruption that they argue brought them to the surface, according to the BBC. These zircon minerals could be anywhere between 1,970 and 600 million years old. Read more

Massive New Volcano May Be Forming In The Pacific

Posted on by
Reply

A scientist from the University of Utah has confirmed that two continent-sized “thermochemical piles” are slowly converging at the bottom of Earth’s mantle about 1,800 miles (2,900 km) beneath the Pacific Ocean. This process, says geologist Michael Thorne, could eventually lead to a cataclysmic eruption that could “cause very massive destruction on Earth.” But don’t panic quite yet. His research suggests that this super-volcano-in-the-making may not erupt for another 100 to 200 million years. Read More