On January 1, 2024 at 16:10:09 JST, an M_(j) 7.6 earthquake struck the Noto Peninsula in the southern part of the Sea of Japan. This location has been experiencing an earthquake swarm for more than three years. Here, ...On January 1, 2024 at 16:10:09 JST, an M_(j) 7.6 earthquake struck the Noto Peninsula in the southern part of the Sea of Japan. This location has been experiencing an earthquake swarm for more than three years. Here, we provide an overview of this earthquake, focusing on the slip distribution of the mainshock and its relationship with the preceding swarm. We also reexamined the source areas of other large earthquakes that occurred around the Sea of Japan in the past and compared them with the Matsushiro earthquake swarm in central Japan from1964 to 1968. The difference between the Matsushiro earthquake swarm and the Noto earthquake swarm is the surrounding stress field. The Matsushiro earthquake swarm was a strike-slip stress field, so the cracks in the crust were oriented vertically. This allowed fluids seeped from the depths to rise and flow out to the surface. On the other hand, the Noto area was a reverse fault stress field. Therefore, the cracks in the earth's crust were oriented horizontally. Fluids flowing underground in deep areas could not rise and spread over a wide area in the horizontal plane. This may have caused a large amount of fluid to accumulate underground, triggering a large earthquake. Although our proposed mechanism does not take into account other complex geological conditions into consideration, it may provide a simple way to explain why the Noto swarm is followed by a large earthquake while other swarms are not.展开更多
The 2024 Noto Peninsula Earthquake was a significant seismic event that caused extensive damage across the region, characterized by a strong shake, subsequent tsunami, fires, liquefaction, and landslides. An emergency...The 2024 Noto Peninsula Earthquake was a significant seismic event that caused extensive damage across the region, characterized by a strong shake, subsequent tsunami, fires, liquefaction, and landslides. An emergency survey was conducted by our team from January 6 to January 8, 2024, focusing primarily on the impact of the earthquake on road bridges. This preliminary report includes ground motion records from the most affected areas and their response spectra, providing insights into the earthquake's intensity and characteristics. Among the key findings, substantial damage was reported to the long-span bridges connecting Noto Island to the mainland,specifically the Noto Island Ohashi Bridge and the Naka-Noto Agriculture Bridge(Twin Bridge Noto). These bridges are crucial as they serve as the sole access points to Noto Island. Additionally, the survey recorded damage to several other structures, including the Okogawa Bridges, Ouchigata Bridge, and a collapsed old wooden bridge.展开更多
On January 1,2024,a devastating M 7.6 earthquake struck the Noto Peninsula,Ishikawa Prefecture,Japan,resulting in significant casualties and property damage.Utilizing information from the first six days after the eart...On January 1,2024,a devastating M 7.6 earthquake struck the Noto Peninsula,Ishikawa Prefecture,Japan,resulting in significant casualties and property damage.Utilizing information from the first six days after the earthquake,this article analyzes the seismic source characteristics,disaster situation,and emergency response of this earthquake.The results show:1)The earthquake rupture was of the thrust type,with aftershock distribution showing a north-east-oriented belt-like feature of 150 km.2)Global Navigation Satellite System(GNSS)and Interferometric synthetic aperture radar(InSAR),observations detected significant westward to north-westward co-seismic displacement near the epicenter,with the maximum horizontal displacement reaching 1.2 m and the vertical uplift displacement reaching 4 m.A two-segment fault inversion model fits the observational data well.3)Near the epicenter,large Peak Ground Velocity(PGV)and Peak Ground Acceleration(PGA)were observed,with the maxima reaching 145 cm/s and 2681 gal,respectively,and the intensity reached the highest level 7 on the Japanese(Japan Meteorological Agency,JMA)intensity standard,which is higher than level 10 of the United States Geological Survey(USGS)Modified Mercalli Intensity(MMI)standard.4)The observation of the very rare multiple strong pulse-like ground motion(PLGM)waveform poses a topic worthy of research in the field of earthquake engineering.5)As of January 7,the earthquake had left 128 deaths and 560 injuries in Ishikawa Prefecture,with 1305 buildings completely or partially destroyed,and had triggered a chain of disasters including tsunamis,fires,slope failures,and road damage.Finally,this paper summarizes the emergency rescue,information dissemination,and other disaster response and management measures taken in response to this earthquake.This work provides a reference case for carrying out effective responses,and offers lessons for handling similar events in the future.展开更多
Earthquakes are caused by the rapid slip along seismogenic faults.Whether large or small,there is inevitably a certain nucleation process involved before the dynamic rupture.At the same time,significant foreshock acti...Earthquakes are caused by the rapid slip along seismogenic faults.Whether large or small,there is inevitably a certain nucleation process involved before the dynamic rupture.At the same time,significant foreshock activity has been observed before some but not all large earthquakes.Understanding the nucleation process and foreshocks of earthquakes,especially large damaging ones,is crucial for accurate earthquake prediction and seismic hazard mitigation.The physical mechanism of earthquake nucleation and foreshock generation is still in debate.While the earthquake nucleation process is present in laboratory experiments and numerical simulations,it is difficult to observe such a process directly in the field.In addition,it is currently impossible to effectively distinguish foreshocks from ordinary earthquake sequences.In this article,we first summarize foreshock observations in the last decades and attempt to classify them into different types based on their temporal behaviors.Next,we present different mechanisms for earthquake nucleation and foreshocks that have been proposed so far.These physical models can be largely grouped into the following three categories:elastic stress triggering,aseismic slip,and fluid flows.We also review several recent studies of foreshock sequences before moderate to large earthquakes around the world,focusing on how different results/conclusions can be made by different datasets/methods.Finally,we offer some suggestions on how to move forward on the research topic of earthquake nucleation and foreshock mechanisms and their governing factors.展开更多
基金supported by the National Nature Science Foundation of China (No. 42130312)。
文摘On January 1, 2024 at 16:10:09 JST, an M_(j) 7.6 earthquake struck the Noto Peninsula in the southern part of the Sea of Japan. This location has been experiencing an earthquake swarm for more than three years. Here, we provide an overview of this earthquake, focusing on the slip distribution of the mainshock and its relationship with the preceding swarm. We also reexamined the source areas of other large earthquakes that occurred around the Sea of Japan in the past and compared them with the Matsushiro earthquake swarm in central Japan from1964 to 1968. The difference between the Matsushiro earthquake swarm and the Noto earthquake swarm is the surrounding stress field. The Matsushiro earthquake swarm was a strike-slip stress field, so the cracks in the crust were oriented vertically. This allowed fluids seeped from the depths to rise and flow out to the surface. On the other hand, the Noto area was a reverse fault stress field. Therefore, the cracks in the earth's crust were oriented horizontally. Fluids flowing underground in deep areas could not rise and spread over a wide area in the horizontal plane. This may have caused a large amount of fluid to accumulate underground, triggering a large earthquake. Although our proposed mechanism does not take into account other complex geological conditions into consideration, it may provide a simple way to explain why the Noto swarm is followed by a large earthquake while other swarms are not.
文摘The 2024 Noto Peninsula Earthquake was a significant seismic event that caused extensive damage across the region, characterized by a strong shake, subsequent tsunami, fires, liquefaction, and landslides. An emergency survey was conducted by our team from January 6 to January 8, 2024, focusing primarily on the impact of the earthquake on road bridges. This preliminary report includes ground motion records from the most affected areas and their response spectra, providing insights into the earthquake's intensity and characteristics. Among the key findings, substantial damage was reported to the long-span bridges connecting Noto Island to the mainland,specifically the Noto Island Ohashi Bridge and the Naka-Noto Agriculture Bridge(Twin Bridge Noto). These bridges are crucial as they serve as the sole access points to Noto Island. Additionally, the survey recorded damage to several other structures, including the Okogawa Bridges, Ouchigata Bridge, and a collapsed old wooden bridge.
基金supported by National High-level Innovative Talents Scientific Research Project in Hebei Province,China(No.405492)JSPS KAKENHI(No.JP19KK0121)National Natural Science Foundation of China(Grant No.42207224).
文摘On January 1,2024,a devastating M 7.6 earthquake struck the Noto Peninsula,Ishikawa Prefecture,Japan,resulting in significant casualties and property damage.Utilizing information from the first six days after the earthquake,this article analyzes the seismic source characteristics,disaster situation,and emergency response of this earthquake.The results show:1)The earthquake rupture was of the thrust type,with aftershock distribution showing a north-east-oriented belt-like feature of 150 km.2)Global Navigation Satellite System(GNSS)and Interferometric synthetic aperture radar(InSAR),observations detected significant westward to north-westward co-seismic displacement near the epicenter,with the maximum horizontal displacement reaching 1.2 m and the vertical uplift displacement reaching 4 m.A two-segment fault inversion model fits the observational data well.3)Near the epicenter,large Peak Ground Velocity(PGV)and Peak Ground Acceleration(PGA)were observed,with the maxima reaching 145 cm/s and 2681 gal,respectively,and the intensity reached the highest level 7 on the Japanese(Japan Meteorological Agency,JMA)intensity standard,which is higher than level 10 of the United States Geological Survey(USGS)Modified Mercalli Intensity(MMI)standard.4)The observation of the very rare multiple strong pulse-like ground motion(PLGM)waveform poses a topic worthy of research in the field of earthquake engineering.5)As of January 7,the earthquake had left 128 deaths and 560 injuries in Ishikawa Prefecture,with 1305 buildings completely or partially destroyed,and had triggered a chain of disasters including tsunamis,fires,slope failures,and road damage.Finally,this paper summarizes the emergency rescue,information dissemination,and other disaster response and management measures taken in response to this earthquake.This work provides a reference case for carrying out effective responses,and offers lessons for handling similar events in the future.
基金supported by U.S.National Science Foundation grant RISE-2425889.
文摘Earthquakes are caused by the rapid slip along seismogenic faults.Whether large or small,there is inevitably a certain nucleation process involved before the dynamic rupture.At the same time,significant foreshock activity has been observed before some but not all large earthquakes.Understanding the nucleation process and foreshocks of earthquakes,especially large damaging ones,is crucial for accurate earthquake prediction and seismic hazard mitigation.The physical mechanism of earthquake nucleation and foreshock generation is still in debate.While the earthquake nucleation process is present in laboratory experiments and numerical simulations,it is difficult to observe such a process directly in the field.In addition,it is currently impossible to effectively distinguish foreshocks from ordinary earthquake sequences.In this article,we first summarize foreshock observations in the last decades and attempt to classify them into different types based on their temporal behaviors.Next,we present different mechanisms for earthquake nucleation and foreshocks that have been proposed so far.These physical models can be largely grouped into the following three categories:elastic stress triggering,aseismic slip,and fluid flows.We also review several recent studies of foreshock sequences before moderate to large earthquakes around the world,focusing on how different results/conclusions can be made by different datasets/methods.Finally,we offer some suggestions on how to move forward on the research topic of earthquake nucleation and foreshock mechanisms and their governing factors.
