What Is Japan’s Nankai Trough Megaquake Advisory?

 Japan's earthquake experts panel chief Naoshi Hirata talks about probability of megaquake on the Nankai Trough; in Tokyo, Japan, 08 August 2024 (issued 09 August 2024) after a magnitude 7.1 earthquake hit southwestern Japan on the day. (EPA/JIJI Press)
Japan's earthquake experts panel chief Naoshi Hirata talks about probability of megaquake on the Nankai Trough; in Tokyo, Japan, 08 August 2024 (issued 09 August 2024) after a magnitude 7.1 earthquake hit southwestern Japan on the day. (EPA/JIJI Press)
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What Is Japan’s Nankai Trough Megaquake Advisory?

 Japan's earthquake experts panel chief Naoshi Hirata talks about probability of megaquake on the Nankai Trough; in Tokyo, Japan, 08 August 2024 (issued 09 August 2024) after a magnitude 7.1 earthquake hit southwestern Japan on the day. (EPA/JIJI Press)
Japan's earthquake experts panel chief Naoshi Hirata talks about probability of megaquake on the Nankai Trough; in Tokyo, Japan, 08 August 2024 (issued 09 August 2024) after a magnitude 7.1 earthquake hit southwestern Japan on the day. (EPA/JIJI Press)

Japan issued its first-ever advisory on higher-than-usual risks of a megaquake, after a strong magnitude 7.1 quake occurred on Thursday at the edge of a tremulous seabed zone along the Pacific coast known as the Nankai Trough.

A possible Nankai Trough megaquake and tsunami disaster could kill hundreds of thousands of people and cause a trillion-dollar damage to Japan.

Here's a look at the risks of what could be the biggest natural disaster in Japan's modern history.

WHAT IS THE NEW RISK OF A MEGAQUAKE?

Japan's Nankai Trough quake advisory panel said the chance of a bigger earthquake striking after a magnitude 7 tremor was once in a few hundred cases, relatively higher than regular times. Earthquakes with a magnitude larger than 8 are considered megaquakes.

Japan estimates the next Nankai Trough megaquake could be as powerful as magnitude 9.1.

University of Tokyo professor Naoshi Hirata, who chairs the panel, said in a press conference that residents in areas that would be hit by such a disaster should review evacuation procedures and stay vigilant for a week.

Japan is one of the world's most earthquake-prone nations sitting on the Pacific "Ring of Fire" arc of volcanoes and oceanic trenches. In 2011, more than 15,000 people were killed in a magnitude 9.0 quake in northeast Japan that triggered a tsunami and triple reactor meltdowns at a nuclear power plant.

WHAT IS NANKAI TROUGH AND WHY IS IT SIGNIFICANT FOR QUAKES?

The Nankai Trough is off its southwest Pacific coast and runs for approximately 900 km (600 miles), where the Philippine Sea Plate is subducting under the Eurasian Plate and the accumulating tectonic strains could result in a megaquake roughly once in 100 to 150 years.

The Japanese government had previously predicted a 70-80% chance of a magnitude 8 to 9 earthquake happening along the Trough in the next 30 years.

The magnitude of an earthquake is related to the length of the fault on which it occurs, according to the United States Geological Survey. The largest earthquake ever recorded was a magnitude 9.5 on May 22, 1960 in Chile on a fault that is almost 1,000 miles long.

THE POTENTIAL DAMAGE FROM NANKAI TROUGH QUAKE AND TSUNAMI

A megaquake could result in maximum measurable tremors to areas from central Shizuoka - about 150 km (93 miles) south of capital Tokyo - to southwestern Miyazaki.

Tsunami of up to 30 meters (98 feet) may reach Japan's Pacific coasts within minutes after the quake, depending on the epicenter and tidal situation.

Coupled with landslides and fire, the disaster would be expected to claim the lives of as many as 323,000 people and destroy 2.38 million buildings, forcing nearly 10 million survivors to evacuate.

Economic damage could total up to 220 trillion yen ($1.50 trillion), or more than a third of Japan's annual gross domestic product, with long-lasting impacts on infrastructure and supply chains for coastal industrial powerhouses producing cars and other key Japanese products.

PREVIOUS NANKAI TROUGH RELATED QUAKES

Nankai Trough earthquakes have been marked on Japan's historic records multiple times since 684, often with accounts of tsunamis striking coastal villages.

The most recent Nankai Trough quake happened in 1946 with magnitude 8.0 tremor and 6.9 meter tsunami, killing 1,330 people.



Puppies Rescued from Flood-Stricken Texas Arrive at Chicago Shelter

 A couple watches a storm passes in the distance, Tuesday, July 15, 2025, in San Antonio. (AP)
A couple watches a storm passes in the distance, Tuesday, July 15, 2025, in San Antonio. (AP)
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Puppies Rescued from Flood-Stricken Texas Arrive at Chicago Shelter

 A couple watches a storm passes in the distance, Tuesday, July 15, 2025, in San Antonio. (AP)
A couple watches a storm passes in the distance, Tuesday, July 15, 2025, in San Antonio. (AP)

Nine puppies from parts of Texas submerged by catastrophic flooding that killed at least 132 people arrived Wednesday at the no-kill shelter PAWS Chicago, joining dozens of puppies that had already arrived.

The critters landed by plane at Waukesha Airport in Wisconsin then made a three-hour journey by van to Chicago.

This is the second batch of pets to arrive in Chicago from Texas. The group Austin Pets Alive!, which has been on the ground in the flood-stricken region since the flooding began, has coordinated the effort with PAWS Chicago.

The animals were in shelters in Texas before the floods began. Organizers say the transfers help those shelters focus on rescuing and reunifying animals separated from their humans by the disaster.

"We’re really happy to be able to support the area by freeing up really needed space in their shelters so they are able to open their shelters to displaced pets," said Celene Mielcarek, PAWS Chicago head of program operations.

PAWS Chicago’s disaster relief program began in 2005 when the organization took in more than 200 pets in the wake of Hurricane Katrina, according to the shelter. Since then, PAWS has rescued pets from areas impacted by Hurricane Helene last year and rescued 33 dogs from Houston shelters after storms in 2023.

Peter Brown, a PAWS volunteer who drove to collect the dogs in Waukesha, said they were anxious on the trip but settled in quickly. He is hopeful the dogs will be quickly adopted.

"They’ll find good homes here," he said. "And then some family who lost their dog in the floods will get it back."

On Monday night, 22 dogs arrived in Chicago from Concho Valley PAWS, a rescue organization in San Angelo, Texas. A total of 31 dogs, ranging from six weeks old to adult dogs, have been relocated to Chicago.

The dogs began receiving medical attention immediately after arriving at PAWS, including being vaccinated, microchipped, and spayed or neutered. They may be ready for adoption and fostering within a few days, according to PAWS.

But for now, they'll get some well-deserved rest, Mielcarek said.

"They’re all pretty tired," she said. "They’re all ready for their dinner."