Biospheric effects of volatiles produced by the Chicxulub Cretaceous/Tertiary impact

Author:: Pope, Kevin O.
Published:: Jun. 14, 1996.
Physical Description:: 1 electronic document

Online Version

hdl.handle.net , Connect to this object online.

Availability

Finding items...

Restrictions on Access:

Unclassified, Unlimited, Publicly available.
Free-to-read Unrestricted online access

Summary:

The meteorite impact that formed the Chicxulub crater 65 million years ago caused a mass extinction of life. Analyses indicate that the projectile was either a 9.4-16.8 km diameter asteroid or a 14.2-24.0 km diameter comet. We estimate that 200 gigatons each of S02 and H2O were deposited globally in the stratosphere by the impact into water saturated sulfate-rich sediments. Conversion of these gases into sulfuric acid aerosols blocked an average of 68 percent of the sun's radiation for a period of 12 years. Global average temperatures probably dropped to near freezing in 5 years and remained near or below freezing for 7 years. Greenhouse warming due to impact-generated C02 was negligible, hence global cooling from sulfates was the major cause of climate change and contributed greatly to the mass extinction.

Other Subject(s):

Environment Pollution

Collection:

NASA Technical Reports Server (NTRS) Collection.

Note:

Document ID: 19960028016.
Accession ID: 96N29121.
NASA-CR-201489.
NAS 1.26:201489.

Terms of Use and Reproduction:

No Copyright.

View MARC record | catkey: 15650426