We know that the Chicxulub impact was responsible for the extinction of land dinosaurs when it crashed to Earth about 66 million years ago. New research shows that the asteroid has also strongly acidified the oceans, wiping out much of its life underwater.
This is the first direct evidence that scientists have found that the effects of the destruction of dino are to blame for the immediate acidification of the waters – enough for the rapid disappearance, which should serve as a warning to us today.
Significant amounts of marine life have been deleted by the Chicxulub asteroid, researchers say; there does not appear to have been a gradual accumulation of acid levels caused by volcanic activity as presented earlier.
"Our data speak to the gradual deterioration of environmental conditions 66 million years ago," says geochemist Michael Henehan, of the German Science Center at GFZ. "Prior to the impact event, we could not find increasing ocean acidification.
" The ocean oxidation we are seeing could easily be a cause of mass extinction in the maritime domain, "says geologist Pinchell Hull of Yale University in Connecticut.
While scientists have suspected for years that an asteroid effect would reduce the ocean's pH (increasing acidity) due to the explosion of sulfur-rich rocks and subsequent acid rain, this was the discovery of a particularly god
The team examined samples of a thick fossil seam left by foraminifera, a tiny plankton from which calcite shells grow, in a cave in Geulherberg in the Netherlands. The element boron (pH indicator) in the shells left behind is exposed to acidification during the extinction of the Cretaceous-Paleogene. "to hennahan called.
"Because so many sediments were laid there at one time, it meant that we could extract enough fossils for analysis and were able to capture a transition."
The impact on the food chain would be enormous, affecting almost every other creature higher up the chain. Organisms such as foraminifera could no longer survive, life forms that feed on them would also be killed, etc. The role of the ocean as carbon sequestration would be greatly reduced as a result.
This study also answers some longstanding questions as to whether the impact of the asteroid is almost completely killed by ocean life, or whether some species (from smaller plankton, i.e., for example) have been able to survive. That's a little of both, says a new study.
In other words, a great loss of species, which starts at 50 percent, followed by a transitional recovery period. This may give experts some fresh clues about how marine life has begun to flourish again – a process that has taken millions of years.
The study is of great importance to us today as well: while radar may not have giant asteroids, increasing carbon dioxide emissions will subsequently increase the ocean's acidity.
As the foraminifera fossils show, this puts the future life of this planet on a flickering earth – burning coal, oil and gas can lower pH more than 66 million years ago, researchers say, though it is important to note that many different factors play out.
"When the asteroid hits, atmospheric CO2 is naturally much higher today and pH much lower," said environmental scientist Phil Williamson of the University of East Anglia in the United Kingdom, who did not participate in the study. told about The Guardian . "In addition, major asteroid strikes cause prolonged darkness.
" However, this study provides further warning that the global changes in ocean chemistry we currently manage can cause highly undesirable and effectively irreversible damage to ocean biology. . "
The study was published in PNAS .