extinction Archives

19 March 2020

Darkness, not cold, likely responsible for dinosaur-killing extinction

New research finds soot from global fires ignited by an asteroid impact could have blocked sunlight long enough to drive the mass extinction that killed most life on Earth, including the dinosaurs, 66 million years ago.

Dinosaur-killing asteroid may have caused global algal bloom, marine extinction

The asteroid impact suspected of killing the dinosaurs may also have triggered a global algal bloom that contributed to a massive marine extinction more than 60 million years ago, according to a new study published in the Journal of Geophysical Research: Planets, a publication of the American Geophysical Union.

Around 66 million years ago, an asteroid 10 kilometers (six miles) in diameter slammed into the Yucatan peninsula, creating a crater 180 kilometers (110 miles) across and 20 kilometers (12 miles) deep. The Chicxulub impact sent tiny spheres of material up into the atmosphere where they became super-heated. Approximately 10²³ of these microscopic spherules were ejected and re-entered the atmosphere to create a global carpet of silica glass 3-millimeters (0.19-inches) thick, known geologically as the Cretaceous-Paleogene layer.

Volcanic eruptions bubbled beneath Earth’s largest extinction

Long before the dinosaurs died off, the “Great Dying” killed nearly all life in the ocean, 70 percent of terrestrial animals and even insects. But this mass extinction more than 250 million years ago – Earth’s greatest natural disaster – is still a scientific mystery. Little evidence remains of why and when life on the planet crashed to this long pause.