New techniques for
dating rocks confirmed that a chain of giant volcanic eruptions 200 million
years ago caused the sudden extinction of half the species now inhabiting the
Earth.
The result of the
research provides far more precise date of when this occurred, for 564 000 201
000 000 000 years ago, in the Triassic extinction event known as Final, or
fourth mass extinction, when the eruption of a volcano chain revolutionized the
climate by emitting large amounts of carbon dioxide into the atmosphere,
according to the report in the journal Science.
Eruptions "had to
be a big event," said study co-author Dennis Kent, an expert in paleomagnetism
Earth Observatory Lamont-Doherty Columbia University in New York. Researchers said that
this event could be a historical parallel of climate change caused by human
activity that takes place in the present day, showing that the dramatic
increase of carbon dioxide may exceed the capacity of vulnerable species to
adapt, Telesur outlined in website. The above estimates
left a margin of one to three million years between the time of volcanic
eruptions and mass extinction occurred at the end of the Triassic. This new
dating places it in 20,000 years at most, a blink in geological terms.
The eruptions caused an
Earth, and quite hot, sweltering become, which ended with plants and animals
and gave way to the Age of Dinosaurs, before they, too, were eliminated from
the Earth 65 million years possibly by another volcanic event combined with a
devastating meteorite.
Volcanoes swept Earth
at a time when most of the land mass conformed one large continent, throwing
10.4 million km3 of lava that eventually broke off and created the Atlantic
Ocean. For this study,
scientists analyzed rock samples from Nova Scotia, Morocco and outside the city
of New York, all of them from the once-united land mass known as Central
Atlantic Magmatic Province. An analysis of the breakdown
of uranium isotopes in basalt, a type of rock left by the eruptions,
researchers gave more precise dates. The eruption in Morocco
was the earliest, followed by Nova Scotia about three thousand years later and
New Jersey 13,000 years later.
The study indicates
that the sediments below are from that period show fossils of Triassic Era.
However above that layer disappear. Some of the creatures
were extinct eel-like fish called conodontas, the first crocodiles and lizards
tree. "In some ways, the
end of the Triassic Extinction is analogous to today," said lead author,
Terrence Blackburn, who conducted the research while working for the
Massachusetts Institute of Technology but is now in the Carnegie Institution. "It could have
happened at a similar time scale. Through the study of the geological data
could be obtained much knowledge of the possible future impact of doubling the
amount of atmospheric carbon dioxide on global temperatures, ocean acidity and
life Earth, "he added. Agencies Sunday March 24,
New techniques for
dating rocks confirmed that a chain of giant volcanic eruptions 200 million
years ago caused the sudden extinction of half the species now inhabiting the
Earth. The result of the
research provides far more precise date of when this occurred, for 564 000 201
000 000 000 years ago, in the Triassic extinction event known as Final, or
fourth mass extinction, when the eruption of a volcano chain revolutionized the
climate by emitting large amounts of carbon dioxide into the atmosphere,
according to the report in the journal Science. Eruptions "had to
be a big event," said study co-author Dennis Kent, an expert in
paleomagnetism Earth Observatory Lamont-Doherty Columbia University in New
York.
Researchers said that
this event could be a historical parallel of climate change caused by human
activity that takes place in the present day, showing that the dramatic
increase of carbon dioxide may exceed the capacity of vulnerable species to
adapt, Telesur outlined in website. The above estimates
left a margin of one to three million years between the time of volcanic
eruptions and mass extinction occurred at the end of the Triassic. This new
dating places it in 20,000 years at most, a blink in geological terms. The eruptions caused an
Earth, and quite hot, sweltering become, which ended with plants and animals
and gave way to the Age of Dinosaurs, before they, too, were eliminated from
the Earth 65 million years possibly by another volcanic event combined with a
devastating meteorite.
Volcanoes swept Earth
at a time when most of the land mass conform one large continent, throwing 10.4
million km3 of lava that eventually broke off and created the Atlantic Ocean. For this study,
scientists analyzed rock samples from Nova Scotia, Morocco and outside the city
of New York, all of them from the once-united land mass known as Central
Atlantic Magmatic Province. An analysis of the
breakdown of uranium isotopes in basalt, a type of rock left by the eruptions,
researchers gave more precise dates.
The eruption in Morocco
was the earliest, followed by Nova Scotia about three thousand years later and
New Jersey 13,000 years later. The study indicates
that the sediments below are from that period show fossils of Triassic Era.
However above that layer disappear. Some of the creatures
were extinct eel-like fish called conodontas, the first crocodiles and lizard’s
tree. "In some ways, the
end of the Triassic Extinction is analogous to today," said lead author,
Terrence Blackburn, who conducted the research while working for the
Massachusetts Institute of Technology but is now in the Carnegie Institution. "It could have
happened at a similar time scale. Through the study of the geological data
could be obtained much knowledge of the possible future impact of doubling the
amount of atmospheric carbon dioxide on global temperatures, ocean acidity and
life Earth, "he added.
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