Natural disasters strike again as Japan experiences a 7.4 earthquake near its Northeastern coast around 5 PM JST on April 20. Within hours, 4 aftershocks were detected. The Pacific Rim has been monitoring for possible tsunamis and volcanic activity for nearly three weeks since Indonesia was struck by the same magnitude on April 1.
While no damages occurred, Japanese Prime Minister Sanae Takaichi urged residents in the affected areas to retreat to higher ground. “Residents in areas where tsunami warnings have been issued should immediately evacuate,” she ordered. Then, she added, “[Authorities are doing] the utmost to assess the damage, implement emergency disaster response measures, such as search and rescue operations, and provide timely and accurate information to the public.”
Where Did Japan’s Earthquake Occur?
According to Earthquake Track, the 7.4 earthquake was detected near the Nippon Trench. Its seismic waves shook the village of Tanohata in the Iwate prefecture. Tanohata’s neighbors, Yamada and Miyako, felt it along with the additional 4 aftershocks. Their magnitude ranged from 4 to 6.
CNN reported that the Japanese national agency mistakenly rated the earthquake at 7.7. Meanwhile, the disaster management division issued evacuations to 171,957 people in the Honshu area. Chief Cabinet Secretary Minoru Kihara has assessed 200 power outages, including train stations.
The Tokyo Electric Power Company confirmed it evacuated its workers from the Fukushima Daiichi and Fukushima Daini nuclear power plants to avoid repeating the 2011 tragedy. The Tonhoku branch has enacted the same procedure for the Onagawa and Higashidori plants.
Indonesia Appears to Have Triggered the Latest Pacific Phenomenon
Seismologists suspected that the 7.4-magnitude earthquake in Indonesia played a role in triggering the latest natural disaster. On April 1, Ternate Island experienced city damage and triggered small tsunamis. The US Geological Survey located its epicenter at 6:48 AM local time.
The townspeople of Bitung felt the tremors, which lasted 10-20 seconds. Then 11 aftershocks occurred, measuring 5.5 on the magnitude scale. Only one person was found dead in the aftermath. Tsunami warnings were immediately issued to the Philippines and Malaysia after the incident.
3 days later, Taiwan was hit by a 5-magnitude tremor in Hualien County. The European-Mediterranean Seismological Center detected it at 5.2, while Italy measured it at 5.5. Taiwan’s disaster response agency only reported minor damage, such as broken windows and fallen shelves.
Nevada soon followed on April 13 with a 5.7-magnitude earthquake. The US Geological Survey (USGS) reported that the epicenter was detected 11 miles from Silver Springs at 6:30 PM Pacific and pinpointed its location in Lyon County. No damage was apparent after the natural disaster.
After the Iwate earthquake, Indonesia and Nevada were reported to have suffered additional earthquakes on April 19. The Malaysian Sun received an official statement from the Indonesian Meteorology, Climatology, and Geophysics Agency. The scientists located a 5.9 tremor within 48 kilometers (~30 miles) northwest of Nias, off of Sumatra Island.
On the same day, the USGS traced a 4.5 tremor from Yerington. Unlike the week before, this mid-range earthquake spawned 60 aftershocks. The Californian coast felt the seismic waves, and they appear to have triggered another one, 62 kilometers (38.5 miles) west of Petrolia.
What to Expect During the Ring of Fire Surveillance
Japan has been prepared since the 2011 earthquake, prioritizing the nation’s safety first. In fact, they conducted the same emergency procedure as in 2025.
On July 29, Russia suffered from an 8.8-magnitude tremor on the Kamchatka Peninsula. Its sheer strength was enough to trigger floods and tsunamis and to reawaken multiple dormant volcanoes in the Ring of Fire. It became the largest strike of the decade, following the 9.1 earthquake in Tohoku, Japan.
The Pacific Islander nation responded quickly by opening emergency shelters for residents from the tsunami-affected coastlines. Former Prime Minister Shigeru Ishiba also ordered the disaster relief staff to prepare water and tents to protect citizens from the 107°F heatwave.
Later, on Dec. 8, Japan was hit by a 7.5-magnitude quake between Chiba and Hokkaido prefectures. Alaska experienced similar results between Dec. 6 and Dec. 7 at the Hubbard Glacier. The events led to Alaska and Canada discovering the Connectors Fault within the Pacific Rim. Seismologist Harold Tobin determined that the fault line’s tectonic plates were damaged by the Kamchatka quake.
Since those major disasters, the Pacific Rim has been actively watching for more tsunamis and volcanic activity. The Iwate earthquake is another lesson learned to improve disaster response and geological discovery. Tsunamis are expected to reach up to 9.8 feet in the Honshu and Iwate coastlines.
