Assertion: earthquake | /r/AtLocation | the region
Facets:
value: frequently
type: TEMPORAL
value: beneath the surface
type: LOCATION
Source sentences:
text: Earthquakes frequently occur in the region at depths of up to 670 kilometres (420 mi) beneath the surface.
text: Firstly, studying earthquake history (e.g. historical and instrumental catalogs of seismicity) and tectonics to assess the earthquakes that could occur in a region and their characteristics and frequency of occurrence.
text: however, very few earthquakes occur in the region less than 100 kilometres (62 mi) deep, the majority originating from a depth of around 250–300 kilometres (160–190 mi).