The number of felt earthquakes in Japan has slightly increased compared to the previous week, with earthquakes being noticeable on the Pacific side of Tohoku and in Hokuriku. Seven earthquakes with a seismic intensity of 3 or higher have occurred from March 27th to April 2nd at 10:00.
In the Noto region of Ishikawa Prefecture, an earthquake estimated to have a magnitude of 4.1 and a depth of 13 km occurred on March 29th with a maximum seismic intensity of 3 observed in Suzu City, Ishikawa Prefecture, and a seismic intensity of 2 in Noto Town. Two additional earthquakes with a magnitude of 3.5 and 3.4 and a depth of 13km each occurred on the same day with a maximum seismic intensity of 3 observed in Suzu City. The Noto region has been experiencing frequent earthquakes since 2021, with active activity since the beginning of the year.
Shallow earthquakes occur inside the Philippine Sea plate, while deep earthquakes occur near the boundary where the Pacific plate subducts into the Philippine Sea plate. Larger earthquakes are more noticeable off the east coast of Hachijojima than in the waters near Hachijojima.
On April 1st, an earthquake with a magnitude of 5.0 and an estimated depth of about 10km occurred off the coast of Shimoetsu, Niigata Prefecture. In this earthquake, a maximum seismic intensity of 3 was observed in Niigata City, Sado City, Yamagata Prefecture, Nakayama Town, Oguni Town, etc.
On January 18th, an earthquake estimated to have a magnitude of 5.4 and a depth of about 30 km occurred with an epicenter in Hyuga-nada, with a maximum seismic intensity of 4 observed in Miyazaki City and Nichinan City. This is the first earthquake with a seismic intensity of 4 or higher with its epicenter in Hyuga-nada since January 22, 2018.
According to the US Geological Survey analysis, there have been three earthquakes with a magnitude of 6 or higher worldwide. The largest quake of magnitude 6.3 occurred off the coast of Chile.
2023/04/02 10:07 Weather News
Earthquakes were conspicuous on the Pacific side of Tohoku and in Hokuriku. Seven earthquakes with a seismic intensity of 3 or higher have occurred. (Tally from March 27th to April 2nd at 10:00)
Japan: A series of seismic intensity 3 earthquakes in the Noto region
At around 12:42, the magnitude was 3.5 and the depth was 13 km. An earthquake with a magnitude of 3.4 and a depth of 13 km also occurred at around 17:39, both of which recorded a maximum seismic intensity of 3 in Suzu City.
The Noto region of Ishikawa Prefecture has been experiencing frequent earthquakes since 2021, and since the beginning of this year there has been active activity, including an earthquake with a maximum seismic intensity of 4 on January 6th.
Please continue to prepare for strong tremors in Suzu City, which is close to the epicenter.
Japan: Earthquake off the coast of Shimoetsu, Niigata Prefecture, with a seismic intensity of 3 for the first time in four years
This is the first time since August 2019 that an earthquake with a seismic intensity of 3 or higher occurred off the coast of Shimoetsu, Niigata Prefecture.
Earthquakes with shallow epicenters occur occasionally off the coast of Shimoetsu, Niigata Prefecture. The most well-known of these is the 1964 magnitude 7.5 Niigata earthquake. The maximum seismic intensity recorded by the Japan Meteorological Agency is 5, but this is because there were few observation points at that time. Areas near the epicenter are believed to have been hit by even stronger tremors, and a tsunami was also generated.
World: M6.3 off the coast of Chile, South America
An earthquake estimated to have a magnitude of 6.3 and a depth of about 12 km occurred with an epicenter off the coast of Chile in South America in the early hours of the 31st (Friday) Japan time. The mechanism of the earthquake is analyzed as a reverse fault type with a pressure axis in the west-northwest-east-southeast direction.
Because the scale of the earthquake was not so large, no strong shaking was transmitted to the land and no tsunami was generated.
Off the coast of Chile, the Nazca Plate is subducting into the South American Plate, and is a region where plate-boundary megaquakes often occur. Seismic activity has been quiet recently, with a shallow earthquake of magnitude 6 or higher not occurring since November last year, and an earthquake of magnitude 7 or higher not occurring since 2016.
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.
As we keep a close eye on seismic activity around the world, recent earthquakes in Japan and off the coast of Chile serve as reminders of the ever-present threat of natural disasters. With ongoing seismic activity in the Noto region of Ishikawa Prefecture and Hyuga Nada, it is important for residents to remain prepared for strong tremors. Meanwhile, the lack of significant seismic activity in Chile in recent years may have led to complacency, but the recent M6.3 earthquake serves as a warning to remain vigilant. Let us all stay informed and prepared for any potential seismic events, and prioritize the safety and wellbeing of ourselves and those around us.