Philippine Standard Time

Masbate stress change model 26Aug2020

The stress change model of the 18 August 2020 Masbate earthquake was calculated from the source fault that was defined using seismicity data. The result shows a NW-SE pattern of stress increase (red shade) at 5 km depth, parallel to the strike of the fault. The stress decrease (blue shade) is observed in areas oblique to the fault. A larger area of increase stress can be observed SE of the epicenter, where most of the aftershocks (with 0-5 km depth) are concentrated. The model suggests that these shallow aftershocks were triggered by the increase in stress caused by the earthquake. We expect more aftershocks to occur in areas with stress increase.