Glaciation on EARTH Magazine

Seafloor volcanism linked to glacial cycles

Wed, 29 Mar 2017 13:57:37 -0400

Sea-level changes related to glacial and interglacial cycles may affect magma production at mid-ocean spreading ridges. Credit: K. Cantner, AGI, and Julia Rosen.

Eruptions from seafloor volcanoes and cycles of global glaciations may seem unrelated, but new research suggests otherwise, indicating that pulses of volcanism at mid-ocean ridges might have influenced glacial and interglacial periods during the latter half of the Pleistocene.

Travels in Geology: Glaciers and grapes in South Australia

Thu, 07 May 2015 10:58:17 -0400

Hallett Cove Conservation Park near Adelaide, Australia, exhibits evidence of a Permian glaciation that occurred when Australia lay at 70 degrees south latitude. Credit: Terri Cook and Lon Abbott.

Without an architecturally stunning opera house, an expansive colorful reef or an iconic redrock outcrop to boast, Adelaide is not usually considered one of Australia’s top travel destinations. But because we love Earth history as well as wine, this town on the southern coast was at the top of our Australian travel itinerary when we found ourselves on sabbatical near Sydney last year. Adelaide is a cosmopolitan city of manageable size, replete with stunning beaches and an especially accessible yet rugged corner of the Outback nearby. Best of all, visitors can observe the handiwork of successive glaciations — which covered the region between 700 million and 280 million years ago — while en route from one cellar door to the next as they tour a world-class South Australian wine region in the picturesque hills just minutes from the city.

New climate record challenges ideas about recent glaciations

Tue, 19 Aug 2014 13:13:21 -0400

Fossilized foraminifera from sediments at sites such as this one at Punta Maiata, Sicily, contributed to a new sea-level and deep-ocean temperature record dating back more than 5 million years. Credit: Eelco Rohling.

Predicting how a changing climate and rising sea levels might impact humans in the future requires an understanding of how Earth has changed in the past. So scientists are continually seeking more and better data to help illuminate earlier conditions.

Ancient volcanic island arc blocked Antarctic current formation

Mon, 09 Sep 2013 14:26:57 -0400

The mountainous spine of South Georgia Island is the Allardyce Range, a displaced fragment of the Andes of southernmost South America. New research suggests such a volcanic island arc blocked the Antarctic Circumpolar Current from forming until 12 million years ago. NASA

There has long been a debate in the geological community over what caused the formation of the Antarctic ice sheet during the Eocene-Oligocene period about 30 million years ago. One of the widely accepted hypotheses is that the glaciation was triggered by the commencement of the Antarctic Circumpolar Current (ACC), an ocean current that circles Antarctica insulating the continent from the warm waters to the north, allowing the ice sheet to remain relatively stable. However, a new study in Geology may invalidate this hypothesis.

Five outstanding questions in earth science

Tue, 26 Jun 2012 19:13:31 -0400

A magma chamber beneath Yellowstone National Park has produced super-eruptions in the past and may do so again someday. Copyright Mary Caperton Morton

Sauropods' massive sizes are well established, but less is known about their biology. Copyright Matt Martyniuk, Creative Commons Attribution-Share Alike 3.0 Unported

Even 15 years after the release of “Good Will Hunting,” there remains something appealing about watching the title character, a mathematically inclined janitor at MIT, scribble the solution to an unsolved mathematics problem on a hallway blackboard. In reality, there are a number of unsolved problems in mathematics, seven of which were designated in 2000 by the Clay Mathematics Institute as “Millennium Prize Problems,” each with a purse of $1,000,000. To date, only one has been solved.

Comet finished off North American big game animals, cooled the planet?

Thu, 05 Jan 2012 06:41:58 -0500

Fires from a comet shower may have killed off the big game in North America about 13,000 years ago, scientists say. Those extinctions have long been attributed either to an abrupt return to glaciation known as the Younger Dryas event or to over-hunting. But now, a team of scientists has found tiny, nanoparticle-sized diamonds in sediments from the Younger Dryas — signs that a cosmic impact may have ultimately been behind both the cold period and the extinctions.