Despite an unusual number of modest earthquakes this year in Southern California, the state overall remains in the midst of a “drought” of major earthquakes.

There have been no significant damaging earthquakes underneath California’s most populous cities in the last 30 years. That’s a stark contrast to the prior three decades, when earthquakes in suburban or mountainous areas caused catastrophic damage in the urban infrastructure, causing freeway and building collapses and resulting in the deaths of scores of people.