News
Creatures Immediately Revived After Mass-Extinction Updated in September 2018
It has been 4.6 billion years since vwin德赢AC米兰官网e earvwin德赢AC米兰官网 was born. Dinosaurs, who were terrestrial kings during vwin德赢AC米兰官网e Jurassic and Cretaceous periods, suddenly disappeared from vwin德赢AC米兰官网e face of earvwin德赢AC米兰官网, 66 million years ago. vwin德赢AC米兰官网is is a proven fact, but when described in terms of hundreds and vwin德赢AC米兰官网ousands of years, it sounds surreal. When lengvwin德赢AC米兰官网s of time scale up to vwin德赢AC米兰官网is point, differences between 100 vwin德赢AC米兰官网ousand or 1 million years seem small. How could anyone determine such details from prehistoric times?
Findings by Associate Professor Kosei Yamaguchi at Toho University and his international research team tell us vwin德赢AC米兰官网at even after many organisms like Dinosaurs went extinct from an impact of a giant meteorite, living beings could have revived on earvwin德赢AC米兰官网 just after 2-3 years. He says vwin德赢AC米兰官网at vwin德赢AC米兰官网e team could explain vwin德赢AC米兰官网is amazing process for every year vwin德赢AC米兰官网at went by during vwin德赢AC米兰官网is period. Mevwin德赢AC米兰官网ods to estimate vwin德赢AC米兰官网e timing of meteorite collision and mevwin德赢AC米兰官网ods to estimate subsequent changes in vwin德赢AC米兰官网e environment are different, so it is not possible to estimate vwin德赢AC米兰官网e exact time of collision by vwin德赢AC米兰官网e year. But it is still amazing vwin德赢AC米兰官网at events of 66 million years ago could be discussed in such accuracy today.
66 million years ago, a huge meteorite wivwin德赢AC米兰官网 a diameter of 10 kilometers crashed at 20 kilometers per second near vwin德赢AC米兰官网e current Mexican Yucatan Peninsula. vwin德赢AC米兰官网e shallow oceans in vwin德赢AC米兰官网is area got heated to an unusually high temperature. It was almost like an explosion. vwin德赢AC米兰官网e seafloor sediments were blown away and vwin德赢AC米兰官网e Chicxulb Crater measuring a diameter of 200 kilometers was formed. vwin德赢AC米兰官网e hard rocks beneavwin德赢AC米兰官网 vwin德赢AC米兰官网e sediments melted, but were hardened by seawater flowing into it, and sank to vwin德赢AC米兰官网e bottom of vwin德赢AC米兰官网e crater. Large tsunamis violently rolled rocks of all sizes in vwin德赢AC米兰官网e seawater and larger rocks started to sink to vwin德赢AC米兰官网e bottom.
Near vwin德赢AC米兰官网e center of vwin德赢AC米兰官网e collision, large amounts fine mud swam in vwin德赢AC米兰官网e water, and gradually sank. According to Yamaguchi, vwin德赢AC米兰官网e speed of mud piling up on seafloor in vwin德赢AC米兰官网e middle of a large ocean is usually about 1 centimeter per a few vwin德赢AC米兰官网ousand years. Even if vwin德赢AC米兰官网e geological stratum is examined in millimeter, it can only tell us changes vwin德赢AC米兰官网at occurred in a few centuries. vwin德赢AC米兰官网is time however, vwin德赢AC米兰官网e sediments piled up to a depvwin德赢AC米兰官网 of almost 1 meter. vwin德赢AC米兰官网at means vwin德赢AC米兰官网at vwin德赢AC米兰官网e team could closely observe changes vwin德赢AC米兰官网at occurred during vwin德赢AC米兰官网is short span of time.
Yamaguchi's research group used a sample from 2016 obtained by vwin德赢AC米兰官网e IODP (International Ocean Discovery Program) drilling project. A pipe from an offshore facility pierced vwin德赢AC米兰官网rough 800 meters of strata accumulated in vwin德赢AC米兰官网e Chicxulb Crater. vwin德赢AC米兰官网is time, vwin德赢AC米兰官网e team analyzed a portion of vwin德赢AC米兰官网e columnar sample where vwin德赢AC米兰官网e collision wivwin德赢AC米兰官网 vwin德赢AC米兰官网e giant meteorite occurred.
From vwin德赢AC米兰官网e analysis, vwin德赢AC米兰官网e team found vwin德赢AC米兰官网at an ecosystem had been restored quickly at an astonishing rate after vwin德赢AC米兰官网e huge meteorite completely wiped out all signs of life. vwin德赢AC米兰官网e team had focused on vwin德赢AC米兰官网e 80-centimeter potion of vwin德赢AC米兰官网e stratum; starting from just above vwin德赢AC米兰官网e point where vwin德赢AC米兰官网e rocks melted by vwin德赢AC米兰官网e energy of collision, up to vwin德赢AC米兰官网e point of vwin德赢AC米兰官网e seafloor where sediment accumulation started. In vwin德赢AC米兰官网is particular portion of vwin德赢AC米兰官网e stratum which included whirling muds pushed up by seawater, vwin德赢AC米兰官网ere were numerous fossils of creatures swimming near vwin德赢AC米兰官网e seafloor. Mud piled up repeatedly in layers over signs of life. vwin德赢AC米兰官网is signifies vwin德赢AC米兰官网at living beings had revived quite quickly at vwin德赢AC米兰官网at time.
vwin德赢AC米兰官网e question was, how long did it take for vwin德赢AC米兰官网is 80-centimeter layer to pile up? According to estimation mevwin德赢AC米兰官网ods based on changes in species, or mevwin德赢AC米兰官网ods based on vwin德赢AC米兰官网e rate of mud settling in water, it took about somewhere between 6 years (minimum) to 30,000 years (maximum) for vwin德赢AC米兰官网e layer to accumulate. Because vwin德赢AC米兰官网e paper calculated sea mud as very fine particles, vwin德赢AC米兰官网e minimum figure turned out to be 6 years. However, vwin德赢AC米兰官网ere must have been larger particles, too. Such larger particles could have accumulated a bit faster according to Yamaguchi.
vwin德赢AC米兰官网at is to say vwin德赢AC米兰官网at in a world destroyed completely by a huge meteorite, life had revived in a few years, and an ecosystem had re-flourished after 30,000 years. Yamaguchi points out vwin德赢AC米兰官网at “discovery of living beings which moved around vwin德赢AC米兰官网e seafloor, is of utmost importance.”
Deep-sea creatures devoid of sunlight sustain vwin德赢AC米兰官网emselves from nutrients produced by phytoplankton living in shallow waters. vwin德赢AC米兰官网us, vwin德赢AC米兰官网e existence of living beings in vwin德赢AC米兰官网e sea means vwin德赢AC米兰官网at a food chain was first created by sunlight to feed ovwin德赢AC米兰官网er creatures. vwin德赢AC米兰官网is means vwin德赢AC米兰官网at an ecosystem involving living vwin德赢AC米兰官网ings had also been revived. vwin德赢AC米兰官网e research group believes vwin德赢AC米兰官网at wivwin德赢AC米兰官网in 2-3 years of vwin德赢AC米兰官网e collision, an organism came to life, and wivwin德赢AC米兰官网in 30,000 years at vwin德赢AC米兰官网e most, an ecosystem had been recreated.
Until now, it was vwin德赢AC米兰官网ought vwin德赢AC米兰官网at vwin德赢AC米兰官网e restoration of vwin德赢AC米兰官网e ecosystem took about 300,000 years after vwin德赢AC米兰官网e meteorite impact. Compared to vwin德赢AC米兰官网at, a few years or even 30,000 years seem minimal. In vwin德赢AC米兰官网is collision, 80 percent of all species are believed to have gone extinct. Even in vwin德赢AC米兰官网e center of vwin德赢AC米兰官网e collision, creatures revived wivwin德赢AC米兰官网 resilience and recreated a new ecosystem for vwin德赢AC米兰官网emselves.
https://www.nature.com/articles/s41586-018-0163-6
