A tsunami warning for the Bay Area after the earthquake in Northern California might have come as a surprise. Here's why it was sent.

Northern California was under a rare and brief tsunami warning alert Thursday that tested local emergency notification systems after a 7.0 magnitude earthquake shook part of the state.The National Weather Service canceled its alert after roughly an hour and before the tsunami was expected to arrive.

A 7.0 magnitude earthquake was reported in northern California on Thursday, according to the United States Geological Survey.

Zoe Mintz explains why a tsunami warning was triggered in the Bay Area after an earthquake in Northern California.

The Pacific West Coast has the highest risk levels of tsunamis in the United States. Here’s where they have stuck in Northern California.