Latest news with #tectonic
Yahoo
04-08-2025
- Science
- Yahoo
Tsunami from 2011 Japan Earthquake Rocks Coast Guard Ship (Video)
In light of the recent tsunami and earthquake news – re: the 8.8-magnitude tremor that struck off the Russian coast, sending tsunami warnings across the Pacific Ocean – the threat of tectonic shifts and resulting massive waves have been top of mind. Like, for instance, looking to the future, with the potential for a massive, catastrophic quake and wave off the coast of Canada. And then looking back in time, mainly to the 2011, 9.0 earthquake and tsunami that hit off Japan, aka the 'Great East Japan Earthquake.' As for that last one, some footage has reemerged, showing a coast guard vessel out in the ocean, and the moment it braced for impact from the surge. See below. The caption reads: 'March 11, 2011 — the day Japan was shaken by one of the deadliest tsunamis in history. A Japanese Coast Guard ship spotted the wave in the distance. They measured it. Timed it. What happened next was caught on camera — as the crew braced for impact, knowing they were heading straight into the heart of the storm.' That earthquake was the most powerful ever recorded in Japan, and the fourth most powerful tremor ever recorded since modern seismology began. It resulted in massive damage, nearly 20,000 deaths, waves reaching up to 133 feet, and the destruction of the Fukushima nuclear plant – an environmental catastrophe still lingering for the tsunami, per Britannica, 'The earthquake triggered tsunami warnings throughout the Pacific basin. The tsunami raced outward from the epicenter at speeds that approached about 500 miles (800 km) per hour. It generated waves 11 to 12 feet (3.3 to 3.6 meters) high along the coasts of Kauai and Hawaii in the Hawaiian Islands chain and 5-foot (1.5-metre) waves along the island of Shemya in the Aleutian Islands chain. Several hours later 9-foot (2.7-metre) tsunami waves struck the coasts of California and Oregon in North America.' Goes to show the destructive and pervasive nature of these natural disasters. And serves as a stark reminder, and warning, for those to from 2011 Japan Earthquake Rocks Coast Guard Ship (Video) first appeared on Surfer on Aug 4, 2025
The Independent
31-07-2025
- Science
- The Independent
Why was the Pacific tsunami smaller than expected? A geologist explains
The earthquake near the east coast of the Kamchatka Peninsula in Russia on July 30 generated tsunami waves that have reached Hawaii and coastal areas of the US mainland. The earthquake's magnitude of 8.8 is significant, potentially making it one of the largest quakes ever recorded. Countries around much of the Pacific, including in East Asia, North and South America, issued alerts and, in some cases, evacuation orders in anticipation of potentially devastating waves. Waves of up to four metres hit coastal towns in Kamchatka near where the earthquake struck, apparently causing severe damage in some areas. But in other places, waves have been smaller than expected, including in Japan, which is much closer to Kamchatka than most of the Pacific rim. Many warnings have now been downgraded or lifted with relatively little damage. It seems that for the size of the earthquake, the tsunami has been rather smaller than might have been the case. To understand why, we can look to geology. The earthquake was associated with the Pacific tectonic plate, one of several major pieces of the Earth's crust. This pushes north-west against the part of the North American plate that extends west into Russia, and is forced downwards beneath the Kamchatka peninsula in a process called subduction. The United States Geological Survey (USGS) says the average rate of convergence – a measure of plate movement – is around 80mm per year. This is one of the highest rates of relative movement at a plate boundary. But this movement tends to take place as an occasional, sudden movement of several metres. In any earthquake of this type and size, the displacement may occur over a contact area between the two tectonic plates of slightly less than 400km by 150km, according to the USGS. The Earth's crust is made of rock that is very hard and brittle at the small scale and near the surface. But over very large areas and depths, it can deform with slightly elastic behaviour. As the subducting slab – the Pacific plate – pushes forward and descends, the depth of the ocean floor may suddenly change. Nearer to the coastline, the crust of the overlying plate may be pushed upward as the other pushes underneath, or – as was the case off Sumatra in 2004 – the outer edge of the overlying plate may be dragged down somewhat before springing back a few metres. It is these near-instantaneous movements of the seabed that generate tsunami waves by displacing huge volumes of ocean water. For example, if the seabed rose just one metre across an area of 200 by 100km where the water is 1km deep, then the volume of water displaced would fill Wembley Stadium to the roof 17.5 million times. A one-metre rise like this will then propagate away from the area of the uplift in all directions, interacting with normal wind-generated ocean waves, tides and the shape of the sea floor to produce a series of tsunami waves. In the open ocean, the tsunami wave would not be noticed by boats and ships, which is why a cruise ship in Hawaii was quickly moved out to sea. Waves sculpted by the seabed The tsunami waves travel across the deep ocean at up to 440 miles per hour, so they may be expected to reach any Pacific Ocean coastline within 24 hours. However, some of their energy will dissipate as they cross the ocean, so they will usually be less hazardous at the furthest coastlines away from the earthquake. The hazard arises from how the waves are modified as the seabed rises towards a shoreline. They will slow and, as a result, grow in height, creating a surge of water towards and then beyond the normal coastline. The Kamchatka earthquake was slightly deeper in the Earth's crust (20.7km) than the Sumatran earthquake of 2004 and the Japanese earthquake of 2011. This will have resulted in somewhat less vertical displacement of the seabed, with the movement of that seabed being slightly less instantaneous. This is why we've seen tsunami warnings lifted some time before any tsunami waves would have arrived there.
ABC News
31-07-2025
- Science
- ABC News
Why the Pacific tsunami was smaller than expected — a geologist explains
The earthquake near the east coast of the Kamchatka peninsula in Russia on July 30 2025 generated tsunami waves that have reached Hawaii and coastal areas of the US mainland. The earthquake's magnitude of 8.8 is significant, potentially making it one of the largest quakes ever recorded. Countries around much of the Pacific, including in east Asia, North and South America, issued alerts and in some cases evacuation orders in anticipation of potentially devastating waves. Waves of up to four metres hit coastal towns in Kamchatka near where the earthquake struck, apparently causing severe damage in some areas. But in other places waves have been smaller than expected, including in Japan, which is much closer to Kamchatka than most of the Pacific rim. Many warnings have now been downgraded or lifted with relatively little damage. It seems that for the size of the earthquake, the tsunami has been rather smaller than might have been the case. To understand why, we can look to geology. The earthquake was associated with the Pacific tectonic plate, one of several major pieces of the Earth's crust. This pushes north-west against the part of the North American plate that extends west into Russia, and is forced downwards beneath the Kamchatka peninsula in a process called subduction. The United States Geological Survey (USGS) says the average rate of convergence — a measure of plate movement — is around 80mm per year. This is one of the highest rates of relative movement at a plate boundary. But this movement tends to take place as an occasional sudden movement of several metres. In any earthquake of this type and size, the displacement may occur over a contact area between the two tectonic plates of slightly less than 400km by 150km, according to the USGS. The Earth's crust is made of rock that is very hard and brittle at the small scale and near the surface. But over very large areas and depths, it can deform with slightly elastic behaviour. As the subducting slab — the Pacific plate — pushes forward and descends, the depth of the ocean floor may suddenly change. A map of tsunami warnings on Wednesday stretching from the west to east of the Pacific Ocean. Nearer to the coastline, the crust of the overlying plate may be pushed upward as the other pushed underneath, or — as was the case off Sumatra in 2004 — the outer edge of the overlying plate may be dragged down somewhat before springing back a few metres. It is these near-instantaneous movements of the seabed that generate tsunami waves by displacing huge volumes of ocean water. For example, if the seabed rose just one metre across an area of 200 by 100km where the water is 1km deep, then the volume of water displaced would fill Wembley stadium to the roof 17.5 million times. A one-metre rise like this will then propagate away from the area of the uplift in all directions, interacting with normal wind-generated ocean waves, tides and the shape of the sea floor to produce a series of tsunami waves. In the open ocean, the tsunami wave would not be noticed by boats and ships, which is why a cruise ship in Hawaii was quickly moved out to sea. Waves sculpted by the seabed The tsunami waves travel across the deep ocean at up to 440 miles per hour, so they may be expected to reach any Pacific Ocean coastline within 24 hours. However, some of their energy will dissipate as they cross the ocean, so they will usually be less hazardous at the furthest coastlines away from the earthquake. The hazard arises from how the waves are modified as the seabed rises towards a shoreline. They will slow and, as a result, grow in height, creating a surge of water towards and then beyond the normal coastline. The Kamchatka earthquake was slightly deeper in the Earth's crust (20.7km) than the Sumatran earthquake of 2004 and the Japanese earthquake of 2011. This will have resulted in somewhat less vertical displacement of the seabed, with the movement of that seabed being slightly less instantaneous. This is why we've seen tsunami warnings lifted some time before any tsunami waves would have arrived there. Alan Dykes, Associate Professor in Engineering Geology, Kingston University. This article is republished from The Conversation under a Creative Commons licence. Read the original article.
Yahoo
30-07-2025
- Science
- Yahoo
Why the Pacific tsunami was smaller than expected
The earthquake near the east coast of the Kamchatka peninsula in Russia on July 30 2025 generated tsunami waves that have reached Hawaii and coastal areas of the US mainland. The earthquake's magnitude of 8.8 is significant, potentially making it one of the largest quakes ever recorded. Countries around much of the Pacific, including in east Asia, North and South America, issued alerts and in some cases evacuation orders in anticipation of potentially devastating waves. Waves of up to four metres hit coastal towns in Kamchatka near where the earthquake struck, apparently causing severe damage in some areas. But in other places waves have been smaller than expected, including in Japan, which is much closer to Kamchatka than most of the Pacific rim. Many warnings have now been downgraded or lifted with relatively little damage. It seems that for the size of the earthquake, the tsunami has been rather smaller than might have been the case. To understand why, we can look to geology. The earthquake was associated with the Pacific tectonic plate, one of several major pieces of the Earth's crust. This pushes north-west against the part of the North American plate that extends west into Russia, and is forced downwards beneath the Kamchatka peninsula in a process called subduction. The United States Geological Survey (USGS) says the average rate of convergence – a measure of plate movement – is around 80mm per year. This is one of the highest rates of relative movement at a plate boundary. But this movement tends to take place as an occasional sudden movement of several metres. In any earthquake of this type and size, the displacement may occur over a contact area between the two tectonic plates of slightly less than 400km by 150km, according to the USGS. The Earth's crust is made of rock that is very hard and brittle at the small scale and near the surface. But over very large areas and depths, it can deform with slightly elastic behaviour. As the subducting slab – the Pacific plate – pushes forward and descends, the depth of the ocean floor may suddenly change. Nearer to the coastline, the crust of the overlying plate may be pushed upward as the other pushed underneath, or – as was the case off Sumatra in 2004 – the outer edge of the overlying plate may be dragged down somewhat before springing back a few metres. It is these near-instantaneous movements of the seabed that generate tsunami waves by displacing huge volumes of ocean water. For example, if the seabed rose just one metre across an area of 200 by 100km where the water is 1km deep, then the volume of water displaced would fill Wembley stadium to the roof 17.5 million times. A one-metre rise like this will then propagate away from the area of the uplift in all directions, interacting with normal wind-generated ocean waves, tides and the shape of the sea floor to produce a series of tsunami waves. In the open ocean, the tsunami wave would not be noticed by boats and ships, which is why a cruise ship in Hawaii was quickly moved out to sea. Waves sculpted by the seabed The tsunami waves travel across the deep ocean at up to 440 miles per hour, so they may be expected to reach any Pacific Ocean coastline within 24 hours. However, some of their energy will dissipate as they cross the ocean, so they will usually be less hazardous at the furthest coastlines away from the earthquake. The hazard arises from how the waves are modified as the seabed rises towards a shoreline. They will slow and, as a result, grow in height, creating a surge of water towards and then beyond the normal coastline. The Kamchatka earthquake was slightly deeper in the Earth's crust (20.7km) than the Sumatran earthquake of 2004 and the Japanese earthquake of 2011. This will have resulted in somewhat less vertical displacement of the seabed, with the movement of that seabed being slightly less instantaneous. This is why we've seen tsunami warnings lifted some time before any tsunami waves would have arrived there. Get your news from actual experts, straight to your inbox. Sign up to our daily newsletter to receive all The Conversation UK's latest coverage of news and research, from politics and business to the arts and sciences. This article is republished from The Conversation under a Creative Commons license. Read the original article. Alan Dykes does not work for, consult, own shares in or receive funding from any company or organisation that would benefit from this article, and has disclosed no relevant affiliations beyond their academic appointment.
Yahoo
22-07-2025
- Science
- Yahoo
In world first, CCTV captures supershear velocity earthquake
Yahoo is using AI to generate takeaways from this article. This means the info may not always match what's in the article. Reporting mistakes helps us improve the experience. Yahoo is using AI to generate takeaways from this article. This means the info may not always match what's in the article. Reporting mistakes helps us improve the experience. Yahoo is using AI to generate takeaways from this article. This means the info may not always match what's in the article. Reporting mistakes helps us improve the experience. Generate Key Takeaways Earthquakes are violent events that alter the face of the planet. In many cases, those changes occur beneath the surface and only gradually become visible over thousands of years. Occasionally, however, an earthquake's effects aren't just felt—they're seen. It's even rarer to actually capture one of those moments on camera, but according to seismologists at Japan's Kyoto University, the footage highlights the first-known video of a strike-slip fault. Their analysis, published in The Seismic Record, has led to new findings based on real-time visual evidence of tectonic motion. The magnitude 7.7 event took place on March 28 along the Sagaing Fault with an epicenter near Myanmar's second-largest city, Mandalay. Although the initial rupture process lasted barely 80 seconds, it and numerous aftershocks were ultimately responsible for 5,456 confirmed deaths and over 11,000 injuries. Later evaluations indicated the quake was the second deadliest in modern history, as well as the most powerful to hit Myanmar in over a century. According to a separate group's paper published in the same journal, the southern portion of the rupture occurred at an astonishing 3.7 miles per second—fast enough to qualify as 'supershear velocity.' Amid the catastrophe, an outdoor CCTV camera about 74.5 miles south of the epicenter recorded a visceral illustration of its power. Over just a few moments, what at first looks like a single chunk of the ground appears to suddenly divide and horizontally shift past one another in opposite directions. Completely by accident, the camera recorded a direct look of a strike-slip fault, something previously analyzed by remote seismic instruments. To researchers at Kyoto University, the clip wasn't just a jaw-dropping scene—it was an opportunity to study a strike-slip fault using visual data. Geologists analyzed the brief video frame-by-frame to learn about the fault shift. Credit: KyotoU / Jesse Kearse 'We did not anticipate that this video record would provide such a rich variety of detailed observations,' corresponding author and geologist Jesse Kearse said in a statement. 'Such kinematic data is critical for advancing our understanding of earthquake source physics.' Kearse and colleagues utilized a technique called pixel cross-correlation to analyze the fault movement on a frame-by-frame basis. Their findings showed the fault slipped horizontally by 8.2 feet in only 1.3 seconds, with a maximum speed of about 10.5 feet per second. While the movement matched experts' existing knowledge of strike-slip ruptures, the short duration and speed were new developments. 'The brief duration of motion confirms a pulse-like rupture, characterized by a concentrated burst of slip propagating along the fault, much like a ripple traveling down a rug when flicked from one end,' Kearse explained. Additional examinations also proved that the slip path was slightly curved, confirming previous observations recorded elsewhere in the world. This means subtly curving strike-slips instead of totally linear ones may be the rule, not the exception. 'Overall, these observations establish a new benchmark for understanding dynamic rupture processes,' the study's authors wrote, adding that the video offers real-time confirmation of curved slip paths while helping 'deepen our understanding of the physical mechanisms that control rapid fault slip during large earthquakes.' Such discoveries may also help seismologists, geologists, and urban planners design more resilient architecture to ensure that when major earthquakes inevitably occur, their damage is minimized as much as possible.
