Angst en waarschuwing voor 'mega-aardbeving' in Japan

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Waarschuwing voor 'mega-aardbeving' in Japan na beving van 7,1

In Japan heeft het meteorologische agentschap JMA voor het eerst een waarschuwing afgegeven voor een 'mega-aardbeving'. Eerder vandaag was er in het zuidwesten van Japan een aardbeving met een kracht van 7,1. Na deze beving is nu een 'mega-aardbevingsadvies' van kracht.

Inwoners van heel West-Japan worden gevraagd om de aankomende week op hun hoede te blijven. Ze moeten op elk moment voorbereid zijn op een nóg sterkere aardbeving, bijvoorbeeld door hun meubels vast te zetten en goed te weten op welke locaties ze kunnen schuilen. Ook wordt gevraagd om afspraken te maken met familieleden om te checken of ze veilig zijn.

Daarnaast geldt voor de kustgebieden van Miyazaki, op het eiland Kyushu, een tsunami-advies. De tsunami's zijn maximaal ongeveer een meter hoog, meldt de Japanse publieke omroep NHK. De mensen in die gebieden wordt opgeroepen om weg te blijven bij de kust en rivieroevers.

De precieze omvang van de schade wordt nog onderzocht, maar duidelijk is wel dat er geen grote ongelukken zijn gebeurd. Volgens NHK zijn er gewonden gevallen in de stad Miyazaki, maar er is niet duidelijk hoe ernstig die verwondingen zijn.

Japan-correspondent Anoma van der Veere:
"Het was een sterke en lange aardbeving maar de reactie erop blijft ingetogen. Japan is stevig gebouwd, zeker als het gaat om aardbevingen. Beelden van omgevallen schappen in de supermarkt, een enkel ingestort huis en schuddende snelwegen komen binnen, maar meldingen van wijdverspreide schade blijven vooralsnog uit. De eerste tsunami's zijn al aangekomen, maar hebben beperkte gevolgen gehad.

Het gevaar is echter niet voorbij. De onderzoekscommissie van het JMA heeft een waarschuwing afgegeven voor een potentiële megabeving langs de 900 kilometer-lange Nankai-breuklijn aan de oostkust van Japan."

De Japanse meteorologische dienst roept mensen in de gebieden op de Nankai-breuklijn op om maatregelen te nemen. Daarmee doelt het JMA op de gebieden waar mogelijk het hypocentrum van de aardbeving ligt: het gebied ondergronds waar een beving ontstaat.

De kans op een mega-aardbeving is groter dan normaal, meldt NHK. Het JMA vraagt mensen om maatregelen te nemen en daarbij te luisteren naar de informatie van de (lokale) overheid.

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Als gevolg van een waarschuwing voor een mogelijke aardbeving zijn er sinds vorige week duizenden hotelreserveringen in Japan geannuleerd.

Deze annuleringen komen op een van de drukste momenten van het jaar voor hoteliers, net voordat een belangrijke feestdag valt waarbij veel Japanners naar hun geboorteplaats reizen om hun voorouders te eren, meldt de Japanse meteorologische dienst.

Verhoogd risico op mega-aardbeving in Nankai-Trog
De Japanse meteorologische dienst heeft een verhoogd risico op een “mega-aardbeving” in de Nankai-trog aangekondigd. Dit gebied strekt zich uit van Shizuoka, ten westen van Tokio, tot het zuidelijkste puntje van het eiland Kyushu. Inwoners van dit gebied zijn aangespoord om voorbereidingen te treffen voor het geval er een zware aardbeving plaatsvindt.

Economische impact
Sinds de waarschuwing hebben minstens 9400 mensen hun hotelreserveringen geannuleerd in het westen van Kochi, een regio die naar verwachting zwaar getroffen zou worden door de eventuele beving. Dit heeft geleid tot een verlies van ongeveer 140 miljoen yen (bijna 870.000 euro) voor de lokale hoteliers tussen 9 en 18 augustus.

De Japanse meteorologische dienst heeft aangegeven de waarschuwing mogelijk donderdag in te trekken als er geen verdere afwijkingen in de seismische activiteit worden gedetecteerd.

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Japan trekt waarschuwing voor 'mega-aardbeving' in, maar gevaar niet geweken

Japan heeft de waarschuwing voor een "mega-aardbeving" donderdag ingetrokken. Het Japanse ministerie van Rampenbestrijding vraagt daarom niet langer om extra waakzaamheid, maar benadrukt dat het gevaar niet volledig is geweken.
De Japanse meteorologische dienst waarschuwde een week geleden voor een megabeving in de Nankaitrog. Het risico op een extreme aardbeving aan de kust was volgens de dienst sterk verhoogd.

Japanse autoriteiten meldden eerder dat de kans groot is dat in de komende dertig jaar een aardbeving met een kracht van 8 of 9 voorkomt. Megabevingen ontstaan gemiddeld eens in de 100 tot 150 jaar in de Nankaitrog.

Deze bevingen hebben in het verleden grote schade aangericht. In het ergste geval kunnen ze honderdduizenden slachtoffers tot gevolg hebben.

Kort voor de waarschuwing vond een beving met een kracht van 7.1 plaats. Daarbij raakten vijftien mensen gewond. Na de waarschuwing annuleerden duizenden toeristen hun vluchten en hotelovernachtingen.

Japan riep burgers op niet te hamsteren, maar gaf wel het advies voorbereidingen te treffen. Zo moesten Japanners evacuatiespullen hebben klaarstaan, zodat ze direct konden vertrekken bij een aardbeving.

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Up to 298,000 could die in Japan in Nankai Trough megaquake: gov't

Up to 298,000 people in Japan could die in a megaquake occurring in the Nankai Trough, a revised estimate by the government's earthquake task force showed Monday, with efforts to mitigate damage reducing the number by around 10 percent from the previous estimate in 2012.

The reduction, however, falls short of the goal of reducing fatalities by around 80 percent set in the government's 2014 basic plan for disaster prevention, highlighting the need for major revisions in evacuation strategies and infrastructure improvements.

In its latest report, the task force projected the number of evacuees would rise from the previous estimate in 2012 of 9.5 million to 12.3 million, equivalent to around 10 percent of Japan's population.

A total of 764 municipalities across 31 of Japan's 47 prefectures would experience shaking measuring at least a lower 6 on the Japanese seismic intensity scale of 7, or tsunami waves at least 3 meters high.

While economic losses are projected to reach up to 270 trillion yen ($1.8 trillion), rising from the previous estimate of 214 trillion yen, the maximum number of buildings expected to be completely destroyed was slightly reduced to 2.35 million due to improvements in residential seismic retrofitting.

According to the report, 215,000 out of the projected 298,000 deaths would be caused by tsunami, based on the assumption that only 20 percent of people would evacuate immediately. Increasing the evacuation rate to 70 percent could reduce the tsunami death toll to 94,000, underscoring the importance of swift evacuation.

The area expected to experience flooding of at least 30 centimeters increased 30 percent from the previous estimate due to advancements in topographical data analysis. The overall death toll is not expected to decline significantly despite seawalls and tsunami evacuation facilities.

Among the scenarios projected, the deadliest involves a magnitude 9-class earthquake occurring on a winter night, with severe damage concentrated in the Tokai region. In this case, the estimated death toll by prefecture would be the highest in Shizuoka at 101,000, followed by Miyazaki at 33,000 and Mie at 29,000.

In addition to the estimated 298,000 direct fatalities, the government also projected for the first time between 26,000 and 52,000 "disaster-related deaths" caused by situations such as deteriorating health conditions in evacuation shelters.

The government will revise its disaster prevention plan to designate additional priority areas based on the expanded flood risk zones, as well as develop a new national resilience plan for fiscal 2026 to 2030 to accelerate infrastructure development. A new agency for disaster prevention will also be established in fiscal 2026.

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Japan steps up earthquake, tsunami defenses amid quake swarm

Authorities have evacuated dozens of people from remote islands in southern Japan that have been shaken by over 1,700 tremors in recent weeks.

The Japanese government on July 1 approved significant upgrades to the national plan to safeguard the public in the event of a major earthquake off southern Japan and to respond in the event that disaster does strike.

The move comes amid an unprecedented swarm of quakes hitting the Tokara Islands.

Dozens of residents of the remote island chain, half-way between Japan's most southerly main island of Kyushu and Okinawa Prefecture, have been evacuated to the mainland after enduring more than 1,700 tremors since June 21.

The islands were hit by 60 quakes on Monday alone, according to the Japan Meteorological Agency, with Akusekijima island shaken by multiple tremors of magnitude 5.

Experts say earthquake swarms have been recorded in the area before, but never of such magnitude or for such an extended period of time.

Authorities have instructed residents who have chosen to remain on the islands to be prepared for further tremors, although they have gone to great lengths to emphasize that the ongoing seismic activity in the Tokara islands is not a precursor to the much-feared Nankai Trough earthquake.

They agree, however, that disaster is unavoidable and edging closer.

Nankai Trough threat
Japan is one of the world's most seismically active countries.

The archipelago, home to around 125 million people, sits on top of four major tectonic plates along the western edge of the Pacific "Ring of Fire."

The nation typically experiences around 1,500 jolts every year and accounts for about 18% of the world's earthquakes of magnitude 6 or greater.

In March, the Japanese government released an updated report on the threat posed by a quake in the Nankai Trough, a 900-kilometer fault that runs parallel to the coast off southern Japan, from Kyushu in the west to Tokyo at its far eastern end.

The study now puts the likelihood of a magnitude-9 quake on the fault at 80% in the next 30 years.

In 2014, a similar report estimated a potential death toll of 332,000 and the destruction of 2.5 million buildings, primarily due to a resulting tsunami impacting coastal communities.

But the revised report now lowered the number of potential fatalities to 298,000, the vast majority of them victims of tsunami waves, while 2.35 million buildings would be destroyed.

In response, the government's Central Disaster Management Council has drawn up new plans, aiming to cut the projected death toll by 80% within the next decade.

Takeshi Sagiya, a professor at Nagoya University's Research Center for Seismology, Vulcanology and Disaster Mitigation, says the 80% target is commendable but probably not achievable in the event of a magnitude-9 disaster.

"The government's priority is to reduce loss of life, but while we learned a lot from the Tohoku earthquake of 2011, we also realized that it is impossible to protect everyone and everything," he told DW.

Taller and more robust sea walls have been constructed in some areas, with hundreds of tsunami refuge towers built in communities identified as most at risk in the event of an earthquake-triggered tsunami. One of the newest is in Kuroshio town in Kochi Prefecture, where experts suggest a tsunami of up to 34 meters tall could come ashore in a worst-case scenario.

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Op vrijdag 4 juli 2025 09:20 schreef Jor_Dii het volgende:
Oei.. als dat maar niet de opmars is naar..

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Authorities have instructed residents who have chosen to remain on the islands to be prepared for further tremors, although they have gone to great lengths to emphasize that the ongoing seismic activity in the Tokara islands is not a precursor to the much-feared Nankai Trough earthquake.

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Tremors shaking Japan's Tokara island chain top 2,000

Weather officials in Japan say the number of tremors that can be felt by humans has topped 2,000 around the Tokara island chain in the country's southwest.

The officials are calling for people to remain vigilant for more earthquakes that could measure lower 6 on the Japanese seismic intensity scale of zero to 7.

Seismic activity intensified on June 21 around the islands of Akusekijima and Kodakarajima, which are part of Toshima Village in Kagoshima Prefecture.

A powerful earthquake measuring lower 6 hit Akusekijima on July 3, followed by two jolts with intensities of upper 5 on July 6. Another quake measuring lower 5 struck on July 7.

The Japan Meteorological Agency says that a total of 2,046 tremors with intensities of one or higher have been observed in the sea off the Tokara islands as of 4 a.m. Tuesday.

There were 83 on Sunday, 39 on Monday and two on Tuesday as of 4 a.m.

The sea off the island chain went through a series of earthquakes in 2021 and again in 2023. But the current swarm has been far larger in terms of the number of jolts.

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Japan updates probability of Nankai Trough megaquake to as high as 90%

Japan’s earthquake panel has revised the 30-year probability of a Nankai Trough megaquake to 60–90%, warning the risk remains imminent and preparedness vital.
A Japanese government panel has updated its assessment of the likelihood of a massive earthquake striking the Nankai Trough off the country’s Pacific coast, setting the probability within the next 30 years at roughly 60 to 90 %, or higher.

The figure, announced Friday by the national earthquake investigation committee, reflects a revised calculation method that factors in data errors and prediction uncertainties. Officials stressed the change does not imply that seismic risk has increased.

Earlier this year, the panel had placed the probability at about 80 %.

“The reality remains that a major quake could occur at any time. Strengthening disaster preparedness must continue,” said panel chief Naoshi Hirata, professor emeritus at the University of Tokyo.

The Nankai Trough, a deep ocean trench along Japan’s Pacific coastline, is known for generating massive tremors every 100 to 150 years. The last confirmed event was the 1946 Nankai quake, which registered an estimated magnitude of 8.0.

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Japan issues warning over MEGAQUAKE that could kill 300,000 people

The Japanese government has issued an urgent warning over the catastrophic damage which could be caused by an impending megaquake.

Experts now believe there is an 80 per cent chance of a magnitude nine tremor occurring in the Nankai Trough off Japan's Pacific coast within the next 30 years.

New government estimates show that this disaster would kill 300,000 in the worst-case scenario.

This includes 215,000 deaths caused by tsunami waves exceeding 30m (98ft) in some areas.

The Nankai Trough is a deep ocean trench formed by the boundary of two tectonic plates, which is hit by a megaquake once every 100 to 200 years.

In the deadliest scenario, the report predicts that 2.35million buildings would be destroyed by collapses, flooding and fires.

The destruction would cause damage worth £1.44trillion (214.2trillion yen) and create 12.3million evacuees.

That is the equivalent of displacing 10 per cent of the Japanese population within a week of the earthquake.

Japan is particularly exposed to deadly earthquakes because it sits on a vast belt of seismic activity known as the Pacific Ring of Fire.

This region is the source of about 81 per cent of the world's large earthquakes due to the meeting of multiple tectonic plates.

One of the most dangerous regions is the Nankai Trench, where the Philippine Sea Plate is pushed beneath the Eurasian Plate.

This 600-mile (900km) trench has the potential to produce extremely large, and exceptionally deadly tremors known as megaquakes.

Last year, the Japanese government issued its first ever Nankai Trough megaquake advisory after a magnitude 7.1 earthquake hit southwestern Japan.

As the risk of a megaquake in the near future increases, the Japanese Cabinet Office has updated its impact estimates for the first time since 2013.

Experts calculated the seismic force of a magnitude nine earthquake in the trench and used this to calculate the flooding and tsunami risk for each part of the country.

This study revealed that stricter building requirements and flood defences have only slightly reduced the estimated deaths over the last decade.

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What happens if a megaquake strikes?
If a megaquake occurs in the Nankai Trough, some regions will have as little as two minutes to prepare.

Waves up to 10m tall will hit Tokyo and 12 other prefectures along the southeast coast.

Kuroshio and Tosashimizu in Kochi Prefecture will be engulfed by a wave 34m (112ft) tall.

As the waves break over the land, flooding of at least 30cm or deeper will cover roughly 444 square miles.

Almost 300,000 people would be killed - including 215,000 killed by tsunami waves, 73,000 by building collapse, and 8,700 in fires.

Post-disaster deaths due to factors like disease and exposure could range from 26,000 and 52,000.

If a megaquake occurs, 10 of the country's 47 administrative prefectures will experience tremors with a rating of seven, the highest score on Japan's earthquake severity scale.

An additional 24 prefectures will experience an earthquake rated at six on the severity scale.

While collapsing buildings will kill an estimated 73,000 people, the deadliest consequence will be the huge tsunami wave sweeping across the island.

When an earthquake occurs beneath the ocean floor, they push massive quantities of water into waves moving as fast as jet planes.

In 2011, a magnitude nine earthquake struck about 81 miles off the coast beneath the North Pacific.

The earthquake produced waves up to 40m (132ft) tall in some places and killed 15,500 people.

In addition, the flooding caused the meltdown of three nuclear reactors at the Fukushima power plant, releasing toxic waste into the environment and forcing thousands to flee their homes.

However, a megaquake in Nankai Trench could be even more devastating than the 2011 Tohoku Earthquake - the most powerful tremor in Japanese history.

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JMA issues advisory of elevated megathrust earthquake risk along Japan Trench after December 8 M7.6 Sanriku quake

Following the M7.6 Sanriku offshore earthquake on December 8, 2025, the Japan Meteorological Agency (JMA) warned that the likelihood of a new large-scale earthquake of Mw8 or higher occurring along the Japan Trench–Kuril Trench has increased relative to normal. While the probability remains low, JMA urged residents of Hokkaido and Tohoku’s Pacific coast to review disaster preparedness and evacuation plans.

Around 90 000 people were evacuated, and between 30 and 35 were injured in northeastern Japan on December 8, after major M7.6 earthquake struck near the coast of Hokkaido.

The earthquake, recorded at 23:15 JST (14:15 UTC), generated small tsunami waves along the Sanriku coast and caused temporary power outages, minor fires, and light structural damage in parts of Aomori, Iwate, and Hokkaido prefectures.

At 02:00 JST on December 9, the Japan Meteorological Agency issued a statement assessing the likelihood of a new large-scale earthquake in northern Japan as relatively higher than normal.

According to the agency, the December 8 earthquake occurred within a seismically active zone influencing the hypothetical source area of a megathrust earthquake along the Japan Trench and Kuril Trench system, which extends from offshore Nemuro in Hokkaido to offshore Sanriku in Tohoku.

The earthquake met the criteria outlined in the national Basic Plan for Promoting Disaster Prevention Measures for Trench-Type Earthquakes Around the Japan Trench and the Kuril Trench, which governs the issuance of information regarding the likelihood of subsequent earthquakes.

The evaluation was based on both the magnitude and the location of the rupture zone, which overlapped with regions capable of generating a trench-type megathrust event.

JMA cited global statistical data covering 1 477 earthquakes of Mw7.0 or higher between 1904 and 2017. Within this dataset, only 17 earthquakes of Mw8.0 or greater occurred within 500 km (310 miles) of a previous Mw7-class event within seven days, representing a frequency of about one in one hundred.

This includes the sequence in March 2011, when an Mw7.3 earthquake off the coast of Sanriku preceded the Mw9.0 2011 Tohoku Earthquake by two days, and the 1963 Etorofu sequence, where an Mw8.5 earthquake followed an Mw7.0 event 18 hours later.

While the probability remains low in absolute terms, JMA says that the current conditions statistically correspond to a period of temporarily elevated risk within the broader Japan Trench–Kuril Trench region.

If a major Mw8+ earthquake were to occur along this trench system, it could produce a large tsunami affecting the Pacific coast from Hokkaido to Chiba Prefecture, with strong shaking across wide areas.

Past geological records compiled by the Central Disaster Prevention Council show that the largest tsunamis along this corridor recur every 300–400 years, and the elapsed time since the last 17th-century event suggests that the region is within an imminent phase of its long-term seismic cycle.

JMA repeated that the advisory does not predict an imminent major earthquake but indicates a relative increase compared with normal background levels.

Residents of Hokkaido, Aomori, Iwate, and Miyagi prefectures, as well as other Pacific coastal areas, are urged to reconfirm evacuation routes and tsunami-safe areas, be prepared to evacuate immediately if strong shaking is felt or a tsunami warning is issued, and follow instructions from national and local disaster management authorities.