2023/12/03 10:22 Weather News
Earthquakes continue to occur frequently on the Pacific coast from Kanto to Tohoku, and earthquakes were also noticeable from Kyushu to Okinawa. No earthquakes with a seismic intensity of 3 or higher have occurred. (Tally from November 27th to December 3rd at 10am)
Domestic: M3.9 earthquake in southern Ibaraki Prefecture, maximum intensity 2
The area around the epicenter of this earthquake can be called an “earthquake hive” and is an area where earthquakes occur very frequently even in the Kanto region. However, there have been relatively few earthquakes this year, with this being the 11th earthquake of magnitude 2 or higher, and only 3 of magnitude 3 or higher. The number of occurrences of earthquakes with an intensity of 3 or higher is the lowest since 2018.
However, earthquakes with a seismic intensity of 4 or higher occur almost every year, so even though the number of earthquakes this year is low, we cannot let our guard down.
World: M7.6 tsunami occurs in the Philippines and reaches Japan
Late at night on the 2nd (Saturday) Japan time, an earthquake estimated to have a magnitude of 7.6 and a depth of approximately 33km occurred off the coast of Mindanao, Philippines. The mechanism of the earthquake is analyzed to be a reverse fault type, with the pressure axis running in the east-west direction.
Because the earthquake occurred relatively close to land, areas close to the epicenter experienced strong shaking. It is estimated that the shaking was around VIII on the revised Mercalli intensity scale, and although it is not possible to make a strict comparison, it was around 5+ on Japan’s seismic intensity scale.
In addition, after this earthquake, there were a series of earthquakes that appeared to be aftershocks, with four earthquakes exceeding magnitude 6 occurring alone.
World: Tsunami of up to 40cm in Izu Islands and Hachijojima
The tsunami reached Japan in the early hours of the 3rd (Sunday), with a maximum height of 40 cm on the Izu Islands and Hachijo Island, and 10 to 20 cm on the Pacific coast from Kanto to Kyushu and Amami. The Japan Meteorological Agency issued a tsunami advisory shortly after the earthquake occurred, and all advisories were lifted at 9:00 a.m. on the 3rd (Sunday).
Large earthquakes frequently occur around the Philippines due to the subduction of the Philippine Sea plate into the Eurasian plate. On the 17th of last month, there was a magnitude 6.7 earthquake in the south of Mindanao. Even if we restrict ourselves to areas near the epicenter of this earthquake, there were earthquakes of magnitude 7.0 in 1991 and magnitude 7.6 in 1989.
M5.5 earthquake in Bangladesh
Because the epicenter was on land, the shaking was somewhat strong near the epicenter, and the shaking was equivalent to V on the revised Mercalli seismic intensity scale, or 4 on Japan’s seismic intensity scale, although a strict comparison is not possible. Although the epicenter was not far from the capital Dhaka, the area affected by the strong shaking was small and no major damage was reported.
Bangladesh is located near the boundary between the Indian plate and the Eurasian plate. Earthquakes with a magnitude of 6 or more occur from time to time, and the most recent one was a magnitude 6.0 earthquake in 1997. There is a very old record of a magnitude 7.1 event occurring in 1918.
Source/Reference
*Information on the epicenter and intensity in Japan is from the Japan Meteorological Agency unless otherwise specified. Information on overseas epicenters is from the United States Geological Survey (USGS) unless otherwise noted. There may be differences in the epicenter information depending on the publishing organization.
2023-12-03 01:22:00
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