Howden Re Japan CEO Kentaro Tada said that while the 7.1-magnitude earthquake that hit Kumamoto Prefecture on July 28 was devastating, with early reports showing dozens of deaths, hundreds of injuries and localized structural damage, insured losses are likely to remain well below those from the 2016 Kumamoto quake and more comparable to the 2024 Noto quake unless a sustained aftershock sequence reveals more widespread damage.
According to the Japan Meteorological Agency, the focal depth of the earthquake was about 10 kilometers and the magnitude was 7.1. The shaking in some areas of Kyushu reached Shinmichi magnitude 7. Authorities warned that the risk of strong aftershocks remained high.
Meanwhile, as Kumamoto is a major semiconductor manufacturing hub, several factories operated by or associated with TSMC/JASM, Sony, Tokyo Electronics and other suppliers have temporarily suspended operations for safety inspections.
Myrto Papaspiliou, Head of International Catastrophe Modeling Research at Howden Re, commented: “The magnitude and depth of this event are similar to the 2016 Kumamoto earthquake, which had a magnitude 7.0 mainshock two days after the initial foreshock and produced relatively severe local shaking, although the footprint was slightly different.
Researchers Ross Stein and Shinji Toda have pointed out that the fault segment south of the rupture has elevated stresses, so this event may have been driven by it.
“Although Japan is one of the most seismically active countries in the world, this area of ​​Kyushu is not associated with its largest subduction zone seismic source.
“The causative fault appears likely to be the southern Hinagu/Yashiro system, and geological evidence suggests that this fault may not have experienced a large surface rupture earthquake for centuries, possibly even millennia.”
Kentaro Tada, CEO of Howden Re Japan, said: “Our current focus is on affected areas across Kyushu. So far, reported damage to Kumamoto Semiconductor infrastructure appears to be limited, but the restart timeline will determine the scale of business disruption losses.”
“It is too early to make formal estimates, but we expect insured losses to be well below the 2016 Kumamoto earthquake and close to the 2024 Noto earthquake, unless the aftershock sequence shows more extensive damage.”
