First Tsunami Waves Reach Japan's Pacific Coast; Continued Vigilance Urged

Today, July 30, the first waves of a tsunami successively reached Japan's Pacific coast. The Japan Meteorological Agency (JMA) and various local governments are strongly urging continued strict vigilance and evacuation until tsunami warnings and advisories are lifted, as there is a possibility that the second and third waves could be higher than the first.

Shortly after 12:00 PM, a 0.3-meter tsunami was observed in Hanasaki, Nemuro City, Hokkaido, while a 0.1-meter (10 cm) wave was reported in Yokohama, Kanagawa. The arrival of the first wave was also confirmed in Owase, Mie. Furthermore, the arrival of the first wave has been reported in wide areas, including the inner part of Tokyo Bay, Sagami Bay/Miura Peninsula, Miyagi Prefecture, and along the Okhotsk Sea coast.

Experts and past examples indicate that tsunamis do not end with the first wave; they can continue for several hours to more than half a day, with subsequent waves carrying the risk of being higher. For instance, in the 1952 Kamchatka earthquake, the largest wave was observed on the Japanese coast several hours after the first wave arrived. A similar phenomenon was also seen during the Great East Japan Earthquake. For this reason, local governments are appealing to residents: "Even if the first wave is small, never let your guard down, and continue to evacuate to higher ground or safe places until the tsunami warning is lifted."

Warnings have been issued to residents who are evacuating, urging them to absolutely avoid dangerous actions such as returning to retrieve belongings or approaching the coast to observe the situation. Additionally, especially in hot regions, people are encouraged to be mindful of heatstroke and ensure adequate hydration.

Currently, tsunami warnings and advisories have been issued across a wide area of the Pacific coast, and relevant agencies continue to exert their full efforts in gathering and disseminating information.

The Context

Japan is highly susceptible to tsunamis due to its location on the Pacific Ring of Fire, a region of intense seismic and volcanic activity. The country lies at the convergence of several major tectonic plates, leading to subduction zones where one plate slides beneath another. This geological activity often generates powerful undersea earthquakes that can displace massive amounts of water, causing tsunamis. Japan has a sophisticated tsunami warning system, developed and refined over decades, largely in response to devastating events like the 2011 Great East Japan Earthquake and Tsunami. Public awareness and preparedness for tsunamis are crucial in Japan, with regular drills and educational campaigns emphasizing the importance of immediate evacuation to high ground upon receiving a warning, regardless of the perceived initial size of the waves, as subsequent waves can often be larger and more destructive.