AIR Analyzes Increased Japan Risk after Tohoku-Oki Earthquake

Catastrophe modeling firm AIR Worldwide has released a new report – “Understanding Earthquake Risk in Japan Following the Tohoku-Oki Earthquake of March 11, 2011.” The report stresses that the “M9.0 Tohoku earthquake changed the seismic risk landscape of Japan. In response, AIR scientists have conducted a detailed analysis of whether and where the stresses relieved by the Tohoku earthquake have been transferred to neighboring faults.”

AIR explained that, “although damage from this event is most closely associated with the massive tsunami—which in places reached a height of more than 30 meters and demolished nearly all structures within its footprint—by AIR’s estimate, the tsunami was responsible for only about 30 percent of overall insured losses from this event. Shake damage was far more widespread—and it is worth remembering that shake damage would have been significant within the area subsequently impacted by the tsunami.”

The paper also analyzes the “effects that stress transfer may have on future rupture probabilities—including on subduction zone segments and crustal faults in the vicinity of Tokyo. For example, AIR’s analysis indicates that the 30-year rupture probability of M ≥ 6.7 earthquakes in the Kanto Plain may have increased from 72 percent to between 81 percent and 93 percent.”

Also discussed in the report is the performance of the current AIR Earthquake Model for Japan in the immediate aftermath of the event.

Source: AIR Worldwide