Scientific Ocean Drilling in the news

A 40,000-year cycle in Earth’s axial tilt influenced subtropical marine productivity about 34 million years ago, during the early expansion of the Antarctic ice sheet, according to a study published in PNAS. The authors link this signal to obliquity-driven Antarctic ice-sheet variability that affected ocean circulation and nutrient delivery far from the polar region.

Cycles in the growth and decay of Antarctica’s ice sheets once shaped marine biological productivity thousands of miles away in the subtropical ocean, according to new research led by scientists at the University of Wisconsin–Madison.

Beneath the surface of the South Atlantic Ocean, scientists have found a hidden but powerful actor in the Earth’s carbon cycle, which has remained undetected in previous research. During recent deep-sea drilling voyages, scientists have found vast reserves of volcanic rubble, called breccia, which have been found to hold much more carbon dioxide than previously detected.

Striking white stucco buildings with cobalt-colored roofs draw millions of tourists each year to Santorini and other Greek islands. But the idyllic setting of the Aegean Sea harbors a hidden secret in the form of a network of underwater volcanoes capable of explosive eruptions. Researchers have now analyzed sediment cores drilled from the flanks of one of the region’s largest underwater volcanoes to estimate its eruption frequency. Explosive eruptions of Kolumbo Volcano occur every few thousand years, on average, the team found, and activity within the next few decades is unlikely.

The Earth’s magnetic poles have reversed 540 times over the past 170 million years. Usually, these reversals are relatively speedy in geological terms, taking around 10,000 years to complete. Now, however, scientists in the US, France and Japan have found evidence of much slower reversals deep in Earth’s geophysical past. Their findings could have important implications for our understanding of Earth’s climate and evolutionary history.

On Friday, Feb. 27, the geology department hosted professor Laura Guertin for a talk titled “Stories of Communicating Scientific Ocean Drilling, From Text to Textiles,” exploring the importance of storytelling in scientific research.

Earth’s magnetic field does not simply switch direction like a flipped light switch. It weakens, wanders, and reorganizes itself over thousands of years before settling again. For decades, researchers believed most of these geomagnetic reversals followed a fairly consistent timeline, usually wrapping up within about 10,000 years.

Many of us learned in school that Earth has seven continents, and the map seemed finished and unchanging. However, scientists have found something beneath the southwest Pacific that changes that view. Zealandia is a huge landmass that fits the scientific definition of a continent, even though almost all of it is underwater.

About 2.7 million years ago, Earth’s climate reached a tipping point that transformed a stable world into one marked by ice ages and abrupt swings. The planet moved from a mostly warm and steady climate to a colder and far more unpredictable one. This change shaped ice ages, oceans, and possibly even human evolution.