2022/09/25 10:16 Weather News
There are many earthquakes from the Kanto region to the Tohoku Pacific Ocean side, and even in western Japan, earthquakes occur in inland areas. Six earthquakes with a seismic intensity of 3 or higher occurred. (September 19th to September 25th at 10:00)
Japan: Numerous faults in southern Hyogo Prefecture
This is the first time since March this year that an earthquake with a seismic intensity of 3 or higher occurred in the southeastern part of Hyogo Prefecture, but it has been 11 years since 2011 that an earthquake like this occurred near Osaka Bay. The earthquake mechanism is analyzed as strike-slip type.
The epicenter of this quake was near the followingshock area of the 1995 Great Hanshin-Awaji Earthquake (Southern Hyogo Prefecture Earthquake). The south side of the Rokko Mountains is a fault zone with many faults, so the activity is believed to have occurred in that area.
The Headquarters for Earthquake Research Promotion estimates that the probability of an earthquake with a magnitude of regarding 7.9 occurring in the Rokko-Awajishima fault zone within the next 30 years is approximately 0% to 1%. More than 25 years have passed since the earthquake, so please pay attention to the surrounding seismic activity once more.
Japan: Suwanosejima volcanic earthquake with a seismic intensity of 2
This earthquake was caused by the volcanic activity of Suwanosejima. According to the Japan Meteorological Observatory, from around 11:50 on the 24th (Sat), there was a temporary increase in volcanic earthquakes with epicenters near the west side of Suwanose Island. Among them, a large earthquake with a maximum seismic intensity of 2 was a felt earthquake.
No particular changes have been observed in the volcanic plume from the Suwanosejima/Mitake crater. Suwanosejima continues to have many eruptions, so caution is required.
Japan: A series of earthquakes occurred in the Kanto region on the 3rd (Sat)
In addition, at around 16:34, an earthquake estimated to have a magnitude of 3.8 and a depth of regarding 50 km occurred in the southern part of Ibaraki Prefecture, and Chikusei City and Bando City in Ibaraki Prefecture, Utsunomiya City in Tochigi Prefecture, Kuki City in Saitama Prefecture, etc. At 17:39, an earthquake with a magnitude of 3.9 and a depth of regarding 40 km occurred with an epicenter in Ibaraki Prefecture, and a seismic intensity of 2 was observed in Hitachi City and Takahagi City, Ibaraki Prefecture.
Both occurred in areas with many earthquakes, and it is thought that it was a coincidence that they occurred one following another on the 3rd (Saturday).
There have been earthquakes as large as M6.0 in the past.
Most of the earthquakes are concentrated at a depth of around 10 km even in the depth of the east-west cross section. There are few occurrences at depths of 20 km or more, but there are a few at depths of 100 km or more. Earthquakes that occur near the boundary between the Pacific plate and the Eurasian plate or within the Pacific plate.
Most deep earthquakes are around magnitude 4, but in May 2014, a large earthquake with a magnitude of 6.0 occurred. In this earthquake, a maximum seismic intensity of 5 lower was observed in Chiyoda Ward, Tokyo, and a seismic intensity of 3 to 4 was observed in a wide area of the Kanto region, causing damage such as injuries.
World: Massive 7.6 earthquake in Mexico
On the 20th (Tuesday) of Japan time, an earthquake estimated to have a magnitude of 7.6 and a depth of regarding 15 km occurred with an epicenter on the Pacific side of Mexico. The earthquake mechanism is analyzed as a reverse fault type with a pressure axis in the north-northeast-south-southwest direction.
Because the epicenter was close to the sea and the scale of the earthquake was large, a tsunami was generated, and the highest point was 79 cm. Strong tremors caused damage to buildings near the epicenter, and local authorities have announced that some people have died.
Also, two days later, on the 22nd (Thursday), an earthquake with a magnitude of 6.8 occurred with an epicenter a little east. It appears to be a series of activity or followingshocks.
The Pacific Ocean side of Mexico is the boundary between the Cocos Plate and the Caribbean Plate, and is an area where large earthquakes occur frequently. In 1995, an earthquake with a magnitude of 8.0 occurred near the epicenter of this earthquake. Also, in 1985, the same local time as this time, an earthquake of magnitude 8.0 occurred on September 19th and became a hot topic.
Magnitude 6.5 earthquake hits southern Taiwan
The earthquake mechanism is analyzed as strike-slip type.
Aftershocks followed one following another, and an earthquake of magnitude 5.5 occurred regarding an hour following the first one. There are concerns regarding damage due to strong tremors around the epicenter.
Reference materials, etc.
*Information on earthquake sources and seismic intensity in Japan is from the Japan Meteorological Agency unless otherwise specified. Overseas epicenter information is from the United States Geological Survey (USGS) unless otherwise specified. There may be differences in hypocenter information depending on the publishing organization.
