Magnitude 6.0 Deep Earthquake Strikes Off Shima, Japan: 352 km Deep, No Tsunami Threat
A magnitude 6.0 earthquake struck off Japan at 22:15 UTC on October 31 (07:15 on November 1, Japan time), about 58 kilometres south-southeast of Shima in Mie Prefecture, at a depth of about 352.4 kilometres, according to the U.S. Geological Survey (USGS). The deep-focus event, catalogued by the USGS as event us7000tuku, has been reviewed by seismologists.
The USGS PAGER system issued a green alert for the quake, indicating a low likelihood of casualties and damage. Sixteen people reported feeling the shaking through the USGS system, and the maximum measured intensity was about III on the Modified Mercalli scale. Because the rupture began more than 350 kilometres underground, the shaking had weakened substantially by the time it reached the surface.
The earthquake posed no tsunami threat: the USGS recorded a tsunami flag of zero, and no warning, watch or advisory was issued. There were no immediate reports of casualties or damage.
Deep-focus earthquakes occur more than 300 kilometres below the surface. The epicentral area lies where the Pacific Plate subducts beneath the Philippine Sea Plate. Such quakes can be felt over a wide area, but their energy dissipates over the long path to the surface, so they typically cause far less damage than shallow earthquakes of the same magnitude.
Source: GSM · USA (original Chinese edition)
Photo: 图：美国地质调查局（USGS）发布的本次地震烈度图，震中位于日本三重县 Shima 市东南偏南约58公里、震源深度约352公里。图片：USGS，公共领域。 / ShakeMap intensity map for this earthquake, released by the U.S. Geological Survey (USGS): epicentre about 58 km south-southeast of Shima, Mie Prefecture, Japan, at a depth of about 352 km. Image: USGS, public domain.
