![A house lies collapsed after an earthquake struck Kumamoto Prefecture, Japan, on July 28. [Xinhua]](https://wimg.heraldcorp.com/news/cms/2026/08/12/9/news-p.v1.20260812.a628856b64fc473789f5ef7d262fc955_P1.jpg)
A powerful earthquake that struck Japan's Kumamoto Prefecture on July 28 caused ground deformation — including vertical displacement and lateral shifts — along roughly 33 kilometers of the active Hinagu fault zone, a joint research team has confirmed. Experts also warned that nearly half of the fault zone has yet to move, raising the prospect of additional earthquakes.
NHK reported Wednesday, citing expert analysis, that the southern half of the roughly 80-kilometer fault zone remains stationary and that long-term preparedness measures against further quakes are needed.
A joint investigation team — including Tohoku University professor Shin Ji Toda and researchers from Kumamoto University — announced after field surveys that ground deformation had been confirmed along approximately 33 kilometers of the Hinagu fault zone, stretching from Mifune-machi to Yatsushiro in Kumamoto Prefecture. Deformation was particularly concentrated along a roughly 20-kilometer stretch running south from Toyono-machi in Uki.
Near Notsu in Hikawa-cho, horizontal displacement of about 1.75 meters was recorded. A vertical step of roughly 1.5 meters was also found near the Yatsushiro junction of the Kyushu Expressway.
The investigation found that a significant number of buildings directly above the fault sustained damage. Even earthquake-resistant housing was confirmed to have suffered harm.
Ground deformation north of Toyono-machi was minor, measuring less than 20 centimeters. The team concluded this was a secondary effect accompanying movement along the main fault that triggered the quake.
"The southern half of the 80-kilometer Hinagu fault zone did not move," Toda said, adding that stress is likely accumulating further in the unruptured southern section and on nearby active faults. "Long-term preparedness is essential," he said.
kate01@heraldcorp.com
