Saturday, November 17, 2012

Extinctions: Asteroid Impacts vs Volcanic Eruptions

The following question indicates that someone was thinking about things - a large step beyond just going to school and memorizing facts.

Hello, I am 20 years old and from Portugal. My question arose when studying for school and noticing that these two events happen, more or less if it can be said on this matter, at the same time. Can a major impact like the one at Chicxulub have enough power to send shock-waves trough the mantel causing the major eruption at the Deccan traps? like if you "squeezed" the Earth and at its weakest point it broke, or like when you give a very strong hit on the top of the bottle and the bottom breaks away because of the pressure and strength that traveled until it finds a blockage it has the power to break through ... We know that earthquakes can be felt thousands of miles away but what happens inside the earth on the mantel at that time? If this is correct where would one get proof?
-Diogo C


You have observed an interesting timing association that has intrigued geologists for a long time.

From Wikipedia ( The Deccan Traps formed at the end of the Cretaceous period. The bulk of the volcanic eruption occurred at the Western Ghats (near Mumbai) some 65 million years ago. This series of eruptions may have lasted less than 30,000 years in total. The original area covered by the lava flows is estimated to have been as large as 1.5 million km², approximately half the size of modern India. The Deccan Traps region was reduced to its current size by erosion and plate tectonics; the present area of directly observable lava flows is around 512,000 km2 (197,684 sq mi).

One website ( offers this observation: "Researchers have simulated the meteorite strike that caused the Chicxulub crater in Mexico, an impact 2 million times more powerful than a hydrogen bomb that many scientists believe triggered the mass extinction of the dinosaurs 65 million years ago. The team's rendering of the planet showed that the impact's seismic waves would be scattered and unfocused, resulting in less severe ground displacement, tsunamis, and seismic and volcanic activity than previously theorized. "

Also from Wikipedia ( is even more specific information about the source of the Deccan Traps: "A geological structure exists in the sea floor off the west coast of India that has been suggested as a possible impact crater, in this context called the Shiva crater. It has also been dated at approximately sixty-five million years ago, potentially matching the Deccan traps. The researchers claiming that this feature is an impact crater suggest that the impact may have been the triggering event for the Deccan Traps as well as contributing to the acceleration of the Indian plate in the early Paleogene. However, the current consensus in the Earth science community is that this feature is unlikely to be an actual impact crater."

The short answer is that the Deccan Traps probably did not cause the extinction that wiped out most of the non-avian dinosaurs, though it may have contributed to making life even more difficult. There appears to be no connection between the Deccan Traps and the Chicxulub event.

On a related tack, the Siberian traps ( 250 million years ago may have contributed to or even caused the Great Dying, the Permian-Triassic extinction event, the most complete extinction event in Earth's history. More than 90% of species living in the Permian era abruptly disappeared at this time.

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