Photograph by Eliseo Fernandez, Reuters
for National Geographic News
Published February 27, 2010
A magnitude 8.8 earthquake struck off the coast of Chile late yesterday evening (10:34 PT), killing scores of people in Chile and causing Hawaii to brace for its biggest tsunami since the Alaskan earthquake of 1964.
(Chile Earthquake Pictures: Quake Spurs Tsunami Threat.)
The tsunami alert went out hours before the first waves, traveling at the speed of a passenger jetliner, were expected to hit Hawaii at 11:19 this morning, local time (Video: Tsunami 101).
Tourists and coastal residents are expected to wake up to tsunami alarms and evacuation instructions several hours earlier, tsunami authorities told the Associated Press (tsunami safety tips).
The earthquake occurred along the junction of the Nazca and South American tectonic plates, which are colliding off the coast of Chile at a rate of 3 inches (80 millimeters) per year (map of Chile).
The coastline of Chile is one of the most active tectonic zones in the world, with 13 temblors of magnitude 7.0 or greater since 1973, the U.S. Geological Survey reports on its earthquake-monitoring Website.
In May, 1960, the same region produced the largest earthquake ever to be measured with modern instruments. That temblor had a magnitude of 9.5 and produced a tsunami that killed 61 people in Hawaii, Japan, and the Philippines.
The greatest safety concerns are in Hawaii, but nevertheless, a region from California to Alaska has been put under a tsunami advisory.
Advisories are the second stage of the National Oceanic and Atmospheric Administration's four-step tsunami warning scale. Rather than urging evacuations, as are being done in Hawaii, an advisory warns of the possibility of strong currents and advises residents to stay out of the water, NOAA's Website explains.
Other scientists, tracking Twitter uses of the word "earthquake" or its equivalent in other languages, have found that the earthquake was felt far enough to set people to tweeting about it to their friends as far away as the Atlantic Coast of Argentina.
"You start getting tweets seconds after an earthquake," says Paul Earle, a seismologist with the United States Geological Survey who uses the system to produce quick reports of earthquake damage. "The system continuously gathers all the tweets, and when there's an earthquake, it pulls out the tweets we think are associated," he says.
No such system yet exists, however, for tracking tsunami reports as waves cross the ocean.
Most Popular News
-
Pictures: Bird Mummies "Fed" After Death, Stuffed With Snails
Some of the millions of ancient Egyptian ibis mummies were "fed" after death, scans reveal—the better to live through the afterlife.
-
Lake Vostok Breached
Russian scientists have confirmed that they have breached the subglacial Lake Vostok in Antarctica—a first.
-
Oldest Animal Discovered?
Could 760-million-year-old African "sponges" be humankind's earliest known ancestors?
Advertisement
From the Web
-
From Huffington Post: Wolf Fosters Kitten
Adorable footage shows a pet wolf looking after a tiny kitty.
-
From Huffington Post: Rare Albino Hummingbird Spotted
The tiny bird was seen visiting a backyard in Virginia.
News Blogs
-
Texas Moves to Save Critical Groundwater
Ogallala Aquifer has dropped as much as 150 feet.
-
Good News, Bad News on U.S. Energy Outlook
The "all of the above" energy approach Obama championed in his State of the Union speech is at odds with U.S. climate goals.
-
Uranus Easy to Find This Week
Thanks to a close encounter with Venus, sky-watchers will have the chance the next few nights to easily glimpse the "green giant" Uranus.
ScienceBlogs Picks
Connect With Nat Geo
Got Something to Share?
Special Ad Section
Great Energy Challenge Blog
Green Living Hot Topics
-
Organic Air Fresheners
Avoid toxic chemicals and create a calming space.
-
Surprising Recyclable Household Items
With a little know-how, you can recycle more than you think.
-
Side Effects of Vegetarianism
Find out how to stay healthy and eat lower on the food chain.
