Latest news with #StevenGoderis
Forbes
29-04-2025
- Science
- Forbes
Life At Impact Site Of Dinosaur-Killing Asteroid Recovered Surprisingly Fast
At the Cretaceous-Paleogene transition 66 million years ago, an asteroid about 10 kilometers in diameter struck a shallow sea in what is today Southeast Mexico. The impact formed the Chicxulub crater, which is around 200 kilometers wide and one kilometer deep. The impact would have thrown trillions of tons of dust into the atmosphere, blocking the sunlight and cooling the Earth's climate significantly. Entire ecosystems collapsed and the impact caused the extinction of 75 percent of all species, including all non-avian dinosaurs. At the impact site every life form was virtually wiped out, but just 30,000 years later marine life flourished thanks to a hydrothermal system created by the asteroid shattering the seafloor. In 2016, an international team of researchers retrieved over 829 meters of cores from within the crater. A new study based on chemical traces and microfossils found in the cores presents evidence that marine life returned to the site of the crater less than a decade after the impact. This rapid recovery was likely helped by a hydrothermal system created by the asteroid impact and a steady supply of nutrients in the crater environment. "After the asteroid impact, the Gulf of Mexico records an ecological recovery process that is quite different from that of the global ocean, as continuous hydrothermal activity has created a unique marine environment," says study lead author Honami Sato, an assistant professor at Japan's Kyushu University. The study hinges on a chemical element called osmium, a metallic element common in asteroids. The researchers found evidence that osmium from the remains of the asteroid buried kilometers beneath the impact crater was continuously released in the Gulf of Mexico as hot water moved beneath the shattered seafloor and up toward the surface. The researchers analyzed the chemical composition of sediments covering the crater to determine the extent of the hydrothermal system and how long the enrichment of osmium lasted. Microfossils preserved in the same sediments allowed the scientists to reconstruct how species diversity changed after the impact. The results show that as the hydrothermal system ceased releasing osmium from the asteroid, the types of marine life living at the crater site changed. When the hydrothermal system was releasing osmium, the dominant plankton were species living in high-nutrient environments. When the osmium returned to pre-impact levels, the plankton changed to species adapted to low-nutrient environments. This finding indicates that the ecosystem was no longer being sustained by the nutrients from the hydrothermal system being released into the overlying ocean. Likely the system was buried to deep by sediments accumulating over time in the basin formed by the impact. "This study reveals that impact cratering events, while primarily destructive, can in some cases also lead to significant hydrothermal activity," concludes coauthor Steven Goderis, a research professor at the Vrije Universiteit Brussel, Belgium. "In the case of Chicxulub, this process played a vital role in the rapid recovery of marine ecosystems." The study,"Prolonged 187Os/188Os excursion implies hydrothermal influence after the Chicxulub impact in the Gulf of Mexico," was published in the journal Nature Communications. Additional material and interviews provided by the University of Texas at Austin.
Yahoo
12-04-2025
- Science
- Yahoo
At the site of the dinosaur-killing crater, scientists find a surprise
When colossal asteroids rock Earth, it's not all doom and gloom. The menacing asteroid that wiped out non-avian dinosaurs left a colossal marine crater in what's now the Yucatan Peninsula. But after analyzing deeply drilled rock core from the impact site created by the six-mile-wide asteroid, geologists have found compelling evidence that life soon thrived in the basin following the seismic episode. The asteroid's impact stoked nutrients and chemicals to be released from beneath the seafloor, a process called hydrothermal activity. Similar activity naturally occurs today in the deep sea, where hydrothermal vents emit superheated chemical-rich fluid into the water, feeding unique colonies of life, including huge tubeworms, crabs, fish, microorganisms, and beyond. "This study reveals that impact cratering events, while primarily destructive, can in some cases also lead to significant hydrothermal activity,' Steven Goderis, a researcher at Vrije Universiteit Brussel in Belgium who co-authored the study, said in a statement. 'In the case of Chicxulub, this process played a vital role in the rapid recovery of marine ecosystems.' SEE ALSO: NASA dropped a new report. It's a wake-up call. The research was published this week in the peer-reviewed journal Nature Communications. The colossal impact event, which triggered a mass extinction event over much of Earth's land and ocean environments, also filled the present-day Gulf of Mexico with nutrients for at least 700,000 years, the researchers concluded. In the core drilled from the impact site, called "Chicxulub crater" (which you should Google for a novel Google-created search result), researchers found a ratio of the metallic element osmium that is associated with asteroid remnants. When the asteroid struck this region, its pulverized particles — which contained osmium — mixed beneath the seafloor and were emitted into the water, before eventually settling back down on the seafloor. When scientists drilled into the ocean bottom, they brought up this ancient seafloor, revealing that hydrothermal fluid containing asteroid remnants flowed into the gulf for hundreds of thousands of years. The impact, which precipitated widespread hydrothermal activity, ultimately created a nutrient-rich oceanic bath, the researchers say. A graphic showing how the environment in the Chicxulub crater following the impact could have spawned rich hydrothermal activity in the enclosed Gulf of Mexico. Credit: Sato et al. A gravity anomaly map of the Chicxulub crater in the Yucatan Peninsula. Credit: NASA Shuttle Radar Topography Mission "After the asteroid impact, the Gulf of Mexico records an ecological recovery process that is quite different from that of the global ocean, as continuous hydrothermal activity has created a unique marine environment," Honami Sato, an earth scientist at Japan's Kyushu University who led the research, explained. If such a cataclysmic event could create extremely habitable conditions on a region of Earth, the same might happen on other worlds, too. It could happen on ocean moons, or in a related way, perhaps even on desert worlds. Mars, for example, is a planet bombarded with meteor strikes. Such impacts could melt the plentiful water ice in parts of Mars' subsurface, creating an inviting environment for microbes to thrive. Fortunately for us earthling land-dwellers, the odds of a cataclysmic space rock impact are exceedingly small. Here are today's general risks from asteroids or comets both tiny and very large. Importantly, even relatively small rocks can still be threatening, as the surprise 56-foot (17-meter) rock that exploded over Russia and blew out people's windows in 2013 proved. Every single day about 100 tons of dust and sand-sized particles fall through Earth's atmosphere and promptly burn up. Every year, on average, an "automobile-sized asteroid" plummets through our sky and explodes, according to NASA. Impacts by objects around 460 feet (140 meters wide) in diameter occur every 10,000 to 20,000 years. A "dinosaur-killing" impact from a rock perhaps a half-mile across or larger happens on 100-million-year timescales.
