Register for an account

X

Enter your name and email address below.

Your email address is used to log in and will not be shared or sold. Read our privacy policy.

X

Website access code

Enter your access code into the form field below.

If you are a Zinio, Nook, Kindle, Apple, or Google Play subscriber, you can enter your website access code to gain subscriber access. Your website access code is located in the upper right corner of the Table of Contents page of your digital edition.

Environment

Deep Rumblings, Part 2

By Rachel PreiserJanuary 1, 1996 6:00 AM

Newsletter

Sign up for our email newsletter for the latest science news

The magnitude 8 earthquake that occurred this past February along the New Guinea Trench, about 45 miles north of Biak Island in the western Pacific, came as a complete surprise to Biak inhabitants and geologists alike. In principle the trench is far from inert: it lies at the boundary where the Australian and Pacific plates collide. The wrinkle of mountains that runs the length of New Guinea, with peaks as high as 15,000 feet, testifies to the power of the collision. Yet the 440-mile-long trench itself had never produced any major tremors. More perplexing still, seismic studies have shown no evidence that ocean crust is being subducted--thrust down into the hot mantle underlying the trench--which is the process that results in quakes at other deep-sea trenches. We see traces of subduction further to the east and west, but not in this particular area, says Northwestern University geophysicist Emile Okal. It may be a very young system, where subduction is just beginning to take place. Biak residents had reason to regret the geologic novelty: the February quake and the resulting 20-foot tsunami killed 100 and washed away more than 600 homes.

    2 Free Articles Left

    Want it all? Get unlimited access when you subscribe.

    Subscribe

    Already a subscriber? Register or Log In

    Want unlimited access?

    Subscribe today and save 70%

    Subscribe

    Already a subscriber? Register or Log In