Isn't it mindboggling: the farther away from the Sumatra "quake" the higher its magnitude as measured by "expert seismologists":
Strong earthquake rocks Indonesia's Sumatra
Saturday, January 1 2005 18:16 Hrs (IST) - World Time -
Jakarta: A large earthquake struck under the sea off Indonesia's Sumatra Islands today (Jan 1, 2005), seismologists said.
The Hong Kong Observatory reported a "severe earthquake" at 06:22 GMT (11:52 hrs IST), with an estimated magnitude of 6.5 on the Richter scale, with its epicentre 350 km west of Banda Aceh.
The quake was close to the epicentre of last Sunday's (Dec 26, 2004) earthquake, which measured 9.0 on the Richter scale and unleashed tsunami, which killed at least 125,000 people around Asia.
An correspondent in Banda Aceh said no tremor was felt there today.
However, the State Seismological Bureau of China (SSB) said the new tremor had a magnitude of 7.0, Xinhua said.
"This is the biggest earthquake we've monitored in the region since December 26 when there were earthquakes of 8.7 and a 7.5 in magnitude," an official with the State Seismological Bureau of China said.
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"It is hard to say if there will be more tsunamis because there are a lot of factors involved."
The US Geological Survey's website said the quake registered 6.5 on the Richter scale at 06:22 GMT (11:52 hrs IST). Thai seismologists measured it at 5.4.
news.indiainfo.com
But then, the US Geological Survey has a rule to sort it out:
In 1935, Charles Richter developed the local magnitude, ML scale for moderate-size (3 < ML < 7) earthquakes in southern California. The ML scale is often called the “Richter scale” by the press and the public. All of the currently used methods for measuring earthquake magnitude (ML, duration magnitude mD, surface-wave magnitude MS, teleseismic body-wave magnitude mb, moment magnitude M, etc.) yield results that are consistent with ML. In fact, most modern methods for measuring magnitude were designed to be consistent with the Richter scale. There is some confusion, however, about earthquake magnitude, primarily in the media, because seismologists often no longer follow Richter's original methodology. Richter's original methodology is no longer used because it does not give reliable results when applied to M >= 7 earthquakes and it was not designed to use data from earthquakes recorded at epicentral distances greater than about 600 km.
earthquake.usgs.gov |
