A meteorite four times the size of Mount Everest crashed into Earth 3.2 billion years ago, triggering a giant tsunami, churning the seafloor, boiling the upper layers of the ocean and kicking up dust that blocked sunlight. But the impact came as a gift for some life forms on Earth.

Scientists on Monday announced the results of their study reconstructing the cascade of events after the meteorite slammed into Earth. Their findings suggest that giant impacts, typically considered as agents of destruction and extinction, could also have conferred short-term benefits to some early microbes.

“We find that early life was resilient in the fact of a giant impact that caused a huge tsunami, boiled the oceans and turned the sky dark,” said Nadja Drabon, assistant professor in the earth and planetary sciences department at Harvard University who led the study. “Life not only recovered quickly, it actually thrived,” she told The Telegraph via email.

The study was published on Monday in the journal Proceedings of the National Academy of Sciences.

Geological evidence suggests that multiple giant meteorites have hit Earth in the past, one such impact about 65 million years ago leading to the demise of the dinosaurs. Some scientists have estimated that giant meteorites pummelled the planet every 15 million years early in Earth’s history.

Drabon and her colleagues analysed geochemical signatures imprinted in layers of rocks in an area in South Africa called the Barberton Greenstone Belt, a site with some of the world’s oldest exposed rocks up to 3.6 billion years old. Earth is about 4.55 billion years old.

Their study has suggested that the meteorite estimated to be 37km to 58km in diameter caused a global tsunami. The impact’s heat partially evaporated the ocean, while the impact’s dust brought darkness that would have killed shallow-water photosynthetic microbes dependent on sunlight.

Microbes in the deep ocean as well as any microbes that could tolerate extreme high temperatures would have been less impacted by the meteorite. The impact also released an abundance of phosphorus into the environment, while the tsunami ferried iron-rich deep water upward near the surface, leading to what the scientists have described as a “temporary bloom” of iron-digesting microbes.

“Imagine such impacts to be giant fertilizer bombs,” Drabon said.

Andrew Knoll, professor of natural history at Harvard University and the study’s co-author, said the large impact on early Earth would have caused widespread mortality. “But in the bacterial world of early Earth, there appear to have been some surprising benefits for survivors — more nutrients,” he told this newspaper. The layers of rock in South Africa representing the post-impact phase suggest that life not only persisted but rebounded rapidly.

“This is exciting and novel work,” said Mukund Sharma, a former scientist at the Birbal Sahni Institute of Paleosciences, Lucknow, who was not associated with the new study. “Their work demonstrates for the first time four processes — the impact, the tsunami, the evaporation of seawater, and the churning of iron from deeper ocean into shallow waters,” he said.

“It also shows that the meteorite brought phosphorus with it,” Sharma said. “This may help resolve our own then puzzling discovery more than three decades ago of phosphorus deposits with microbes from a three billion-year-old site in Karnataka.”

Sharma and his colleagues had detected phosphorus with ancient cyanobacteria in the three billion-year-old rocks from what geologists call the Dharwar craton and published the findings in 1990. “At the time, we couldn’t explain the source of the phosphorus — this work shows a meteorite as the source.”

“We know at least 16 giant meteorites impacted Earth during its early history — it is possible that three billion years ago, there was another impact,” Sharma said.