Would you like to start a free subscription?
Remember me | Forgot password
For full content view: Log in Now!
New mass-extinction mechanism. It is not only difficult to find consensus on exactly how many mass extinction events have occurred in Earth’s history, but even more difficult to determine their causes. Besides meteorites, the most widely accepted causes of mass extinction include glaciation, volcanism and the formation/glaciation of the mega-continents Gondwana and Pangea.
New research was presented in January at the American Astronomical Society meeting supporting the idea that a lesser-known extinction – the Pliocene-Pleistocene boundary 2 million years ago – was caused by cosmic rays from a nearby supernova (a massive exploding star). Narcisco Benítez at John Hopkins University in Baltimore, Maryland, and Jesús Maíz Appellániz of the Space Telescope Science Institute in Virginia traced the motion of a cluster of young, short-lived stars formed from the debris of about 20 supernovae that have exploded over the last 20 million years. The cluster, called the Scorpius-Centaurus OB association, passed within 130 light-years of Earth about two million years ago.
This area of the site is restricted.
In order to gain access, please either Log
In, or subscribe to World Oil.
Two options are available to you for creating an account.
1. Get a Free Trial Subscription to World Oil Magazine and gain immediate access to select content on World Oil Online.
Start a Free Trial Subscription and gain immediate access to the complete current issue of World Oil Magazine. Plus, you’ll receive 3 upcoming issues of World Oil Magazine in print or digital format.* You also receive access to the Energy Events Calendar, Industry Statistics and WO Wire’s news and industry coverage.
2. Purchase a subscription to World Oil magazine and gain immediate
and complete access to World Oil Online. As a Total Access subscriber
you will have access to all areas of the site available to registered users and
free subscribers as well as having access to such premium content areas as:
Physical copies of this content may be available for purchase. Visit the Reprints & Back Issues section.
If you are already a paid subscriber and do not have access, please email CustomerService@worldoil.com.
World Oil's specialized upstream Engineering Data Tables featuring the Drill Bit Classifier, Tubing Tables and more. Get Total Access today.
Kuala Lumpur - March 25-28
The Woodlands, TX - April 1-3
Houston, TX - April 6-9
All material subject to strictly enforced copyright laws.
© 2014 World Oil. © 2014 Gulf Publishing Company.