2022/05/01 10:32 Weathernews
There were relatively few earthquakes on the northeastern Pacific side, and the occurrence of earthquakes was somewhat conspicuous in western Japan. There have been two earthquakes with a seismic intensity of 3 or higher. (April 25-May 1 10:00 total)
Domestic: M4.1 and M4.2 in the southern part of Kyoto Prefecture, almost the same epicenter as March 31
In addition, an earthquake with a magnitude of 4.2 and an estimated depth of about 20 km occurred around 18:06 on Saturday, 30th, and Kyoto City, Kyoto Prefecture, Kameoka City, Nantan City, Nose Town, Osaka Prefecture, and Sanda, Hyogo Prefecture. A maximum seismic intensity of 3 was observed in cities and other places. The mechanism of each earthquake is analyzed as a strike-slip type.
Epicenter concentrated in a narrow area
It was the 8th felt earthquake in about a month. Of the eight earthquakes, the seven earthquakes for which provisional values have been analyzed are considered to be a series of activities with almost the same epicenter at a depth of 13 to 14 km. Even if you look at the epicenter distribution with a small earthquake, you can see that it is concentrated in a very narrow range.
It is believed that there is an active fault called the Kameoka Fault in the north of Kameoka City, Kyoto Prefecture. However, it cannot be concluded that the activity of this fault is due to the fact that it is a reverse fault that rises to the northeast and there is a slight difference in the mechanism from this series of strike-slip type earthquakes.
Since the activity of the earthquake continues to be active, it is necessary to be careful about shaking with a seismic intensity of about 3 to 4 for a while.
Domestic: Earthquake with a maximum seismic intensity of 3 in Yamaguchi Prefecture
Central Yamaguchi Prefecture is not an area where earthquakes occur frequently, and earthquakes of magnitude 4 and above have been occurring since 1997. The earthquake that occurred on June 25, 1997 was in the area north of the epicenter this time, but we have observed a magnitude of 6.6 and a maximum seismic intensity of over 5.
This earthquake occurred far from the active faults known in Yamaguchi Prefecture. According to the evaluation by the Headquarters for Earthquake Research Promotion of the government, the activity of the Suo-nada fault zone distributed off the coast of Yamaguchi Prefecture is the most concerned, and the probability that an earthquake with a magnitude of 7.6 will occur within the next 30 years is 2 to 4%. It has been.
Domestic: M4.4 in southern Kyoto
These earthquake swarms often occur in the waters near the Tokara Islands. Recently, earthquakes have occurred frequently since April 9th this year, and on April 10th, more than 100 felt earthquakes occurred in one day. During the three days from the 10th to the 12th, which was the peak of activity, we observed 229 felt earthquakes, 15 seismic intensity 3 and 5 seismic intensity 4.
In many cases, the active situation from past activities lasts for several days, and the maximum seismic intensity may reach a little over 4-5. It is necessary to be careful about strong shaking for a while.
World: Frequent M5 earthquakes in the Mediterranean
From Wednesday 27th to Friday 29th Japan time, earthquakes of magnitude 5 occurred one after another in the Mediterranean Sea. On the 27th (Wednesday), a magnitude of 4.9 occurred on the southern seas of Greece, a magnitude of 4.9 occurred on the coast of Cyprus, and a magnitude of 4.9 occurred on the island of Crete on the 29th (Saturday).
Since the magnitude of the earthquake is not so large and the epicenters are a little far apart, it seems that the activities are not directly related. What they have in common is that they are near the boundary between the African plate and the Eurasian plate. (There is also a view that the northern plate is classified into the Aegean plate and the Anatolian plate.)
Although there was no noticeable damage in this series of earthquakes, strong earthquakes in the latter half of Tude 6 have occurred in the mug in the past. In January of this year, there was a magnitude 6.6 earthquake in the waters near Cyprus. Since it is an area with a high risk of earthquakes, future activities will be watched.
M5.0 earthquake in the middle of Africa
Most African earthquakes occur around the Great Rift Valley. The African Continent is made up of African plates, and the Great Rift Valley is thought to be the area where the plates are being torn. In its activities, it has caused earthquakes, and in the past, magnitude 7 class earthquakes have also occurred.
Reference materials, etc.
* Information on the epicenter and seismic intensity in Japan is from the Japan Meteorological Agency unless otherwise stated. Information on overseas epicenters is from the United States Geological Survey (USGS) unless otherwise stated. The epicenter information may differ depending on the issuing organization.