Simply put, it was a bad day for Earth when an asteroid hit Mexico’s Yucatan Peninsula 66 million years ago. This is what caused a global catastrophe, wiping out three-quarters of the world’s species and ending the age of the dinosaurs.
Quoting Reuters, the direct impacts include forest fires, earthquakes, huge shock waves in the air and huge standing waves in the ocean. But the biggest impact for many species may be the climate catastrophe that occurs in the following years when the sky darkens with clouds of debris and temperatures drop.
Researchers on Monday, United States time or Tuesday, October 31 2023 WIB, revealed the powerful role dust from rock fragments thrown into the atmosphere from the impact site may have played in driving extinction, choking the atmosphere and preventing plants from utilizing sunlight as energy that sustains life in the world. a process called photosynthesis.
The total amount of dust, according to their calculations
about 2,000 gigatons – more than 11 times the weight of Mount Everest.
The researchers ran paleoclimate simulations based on sediments excavated at a North Dakota paleontological site called Tanis that preserve evidence of post-impact conditions, including huge dust impacts.
Simulations show this fine-grained dust can block photosynthesis for up to two years by making the atmosphere opaque to sunlight and remain in the atmosphere for 15 years, said planetary scientist Cem Berk Senel of the Royal Observatory of Belgium and Vrije Universiteit Brussel.
Although previous research highlighted two other factors – sulfur released after crashes and soot from forest fires – this study suggests that dust plays a bigger role than previously known.
The dust – silicate particles measuring about 0.8-8.0 micrometers – that makes up the global cloud layer is produce from granite and gneiss rocks shattered by the powerful impact that tore a hole in the Chicxulub (pronounced CHIK-shu-loob) crater of Yucatan, 112 miles (180 km) ) is 12 miles (20 km) wide and 12 miles (20 km) deep.
As a result, the Earth experienced a decrease in surface temperature of around 27 degrees Fahrenheit (15 degrees Celsius).
“It was cold and dark for years,” said Vrije Universiteit Brussel planetary scientist and study co-author Philippe Claeys.
Earth experienced an impact winter
with global temperatures plummeting and primary productivity – the processes used by land and aquatic plants and other organisms to make food from inorganic sources – collapsing, causing a chain reaction of extinctions. When plants die, herbivores starve. Carnivores left with out prey and perish. In the marine world, the death of small phytoplankton causes the destruction of the food web.
“While sulfur lasts about eight to nine years, soot and silicate dust remain in the atmosphere for about 15 years after impact. Complete recovery from winter impacts takes longer, with pre-impact temperature conditions returning after about 20 years. ,” said Royal Observatory of Belgium planetary scientist and study co-author Özgür Karatekin.
The asteroid, estimated to be 6-9 miles (10-15 km) wide, brought the Cretaceous Period to a violent end.
Dinosaurs, apart from their bird descendants, also became extinct, as did the marine reptiles that dominated the oceans and many other groups. The biggest beneficiaries are mammals, which have only played a small role in the drama of life but have been given the opportunity to become the main characters.
“Biotic groups that are not adapted to survive in conditions of darkness, cold and lack of food for almost two years will experience mass extinction,” said Karatekin. not relying on one particular food source – generally survive better, such as small mammals.”
Without this disaster, dinosaurs might still dominate today. “Dinos dominated Earth and were fine when the meteorite hit,” Claeys said.