Ancient megavolcanoes killed half the world's species

A view of Tungurahua volcano errupting, seen from La Florida, Ecuador on December 20, 2012. New rock dating techniques have helped narrow the timeframe of a chain of massive volcanic eruptions that wiped out half the world's species 200 million years ago, a study said Thursday

New rock dating techniques have helped narrow the timeframe of a chain of massive volcanic eruptions that wiped out half the world's species 200 million years ago, a study said Thursday.

The result is the most precise date yet -- 201,564,000 years ago -- for the event known as the End-Triassic Extinction, or the fourth mass extinction, said the study in the journal Science.

The eruptions "had to be a hell of an event," said co-author Dennis Kent, a paleomagnetism expert at Columbia University's Lamont-Doherty Earth Observatory.

They may offer a historic parallel to the human-caused climate change happening today, by showing how sharp increases in carbon dioxide can outpace vulnerable species' ability to adapt, researchers said.

The new analysis winnows the estimated date from its previous range of up to three million years to 20,000 years at most, a blink of an eye in geological terms.

The eruptions caused an already hot Earth to become even more stifling, killing off plants and animals and making way for the age of the dinosaurs -- before they, too, were obliterated some 65 million years ago, possibly by another volcanic event combined with a devastating meteorite strike.

Volcanoes roiled the Earth in a time when most of the land mass was united in one big continent, spewing some 2.5 million cubic miles of lava that, over time, split the terrain and led to the creation of the Atlantic Ocean.

For the study, scientists analyzed rock samples from Nova Scotia, Morocco and outside New York City, all of which came from this once-united landmass known as the Central Atlantic Magmatic Province.

An analysis of the decay of uranium isotopes in the basalt, a type of rock left by the eruptions, offered researchers more precise dates.

The eruption in Morocco was the earliest, followed by Nova Scotia about 3,000 years later and New Jersey 13,000 years later.

Sediments that lie below that time hold fossils from the Triassic era. Above that layer, they disappear, the study said.

Some of the lost creatures include eel-like fish called conodonts, early crocodiles and tree lizards.

"In some ways, the End Triassic Extinction is analogous to today," said lead author Terrence Blackburn, who carried out the study while at the Massachusetts Institute of Technology but is now with the Carnegie Institution.

"It may have operated on a similar time scale. Much insight on the possible future impact of doubling atmospheric carbon dioxide on global temperatures, ocean acidity and life on earth may be gained by studying the geologic record."

Comments

Why States Still Use Barrel Bombs

Smoke ascends after a Syrian military helicopter allegedly dropped a barrel bomb over the city of Daraya on Jan. 31.(FADI DIRANI/AFP/Getty Images) Summary Barrel bombs are not especially effective weapons. They are often poorly constructed; they fail to detonate more often than other devices constructed for a similar purpose; and their lack of precision means they can have a disproportionate effect on civilian populations. However, combatants continue to use barrel bombs in conflicts, including in recent and ongoing conflicts in Africa and the Middle East, and they are ideally suited to the requirements of resource-poor states. Analysis Barrel bombs are improvised devices that contain explosive filling and shrapnel packed into a container, often in a cylindrical shape such as a barrel. The devices continue to be dropped on towns all over Syria . Indeed, there have been several documented cases of their use in Iraq over the past months, and residents of the city of Mosul, which was re

Russia Looks East for New Oil Markets

Click to Enlarge In the final years of the Soviet Union, Soviet leader Mikhail Gorbachev began orienting his foreign policy toward Asia in response to a rising Japan. Putin has also piloted a much-touted pivot to Asia, coinciding with renewed U.S. interest in the area. A good expression of intent was Russia's hosting of the Asia-Pacific Economic Cooperation summit in 2012 in Vladivostok, near Russia's borders with China and North Korea. Although its efforts in Asia have been limited by more direct interests in Russia's periphery and in Europe, Moscow recently has been able to look more to the east. Part of this renewed interest involves finding new export markets for Russian hydrocarbons. Russia's economy relies on energy exports, particularly crude oil and natural gas exported via pipeline to the West. However, Western Europe is diversifying its energy sources as new supplies come online out of a desire to reduce its dependence on Russian energy supplies . This has

LONDON POLICE INDIRECTLY ENCOURAGE CRIMINALS TO ATTACK RUSSIAN DIPLOMATIC PROPERTY

ILLUSTRATIVE IMAGE A few days ago an unknown perpetrator trespassed on the territory of the Russian Trade Delegation in London, causing damage to the property and the vehicles belonging to the trade delegation , Russian Foreign Ministry Spokeswoman Maria Zakharova said during the September 12 press briefing. The diplomat revealed the response by the London police was discouraging. Police told that the case does not have any prospects and is likely to be closed. This was made despite the fact that the British law enforcement was provided with video surveillance tapes and detailed information shedding light on the incident. By this byehavior, British law inforcements indirectly encourage criminals to continue attacks on Russian diplomatic property in the UK. Zakharova’s statement on “Trespassing on the Russian Trade Mission premises in London” ( source ): During our briefings, we have repeatedly discussed compliance with the Vienna Convention on Diplomatic Relations, specif

Search This Blog