The impacts of a tsunami stemming from the underwater eruption of the Hunga Tonga-Hunga Ha’apai volcano on Saturday morning are expected to go on for several hours around the Bay Area, with some of the first harbor flooding seen in Santa Cruz.

The satellite images have been dramatic of the undersea volcanic eruption — the second time this volcano has erupted in the last eight years, with a 2014 eruption creating a new island that has been growing in recent weeks with increased volcanic activity.

A tsunami warning was issued Saturday morning for all of the West Coast, including the San Francisco Bay Area, beginning around 7:30 a.m. And there's been a new round of meteorologists and experts explaining that tsunamis aren't usually the visible tidal waves people imagine, but are more like very high tides. Combined with January King Tides, this could mean flooding in many places.

Posting a video of the tsunami hitting Tonga, Weather West's Daniel Swain writes, "A visual reminder that tsunamis are *not* like a single big ocean wave: they are a series of successive surges of water that may be only a few feet in height yet still contain a massive amount of energy and can affect bays and inlets otherwise protected from ocean waves." And Swain suggested that around the Bay Area, the surge will be "Disruptive, but not destructive in most cases," but it's "Still a good idea to stay away from immediate shoreline!"

In Santa Cruz Harbor, the tsunami surge became evident around 8 a.m. on Saturday, with cars parked nearby already half-submerged.

A San Francisco Fire Department truck was rolling along the Great Highway Saturday morning, alerting everyone near Ocean Beach to the tsunami warning, and telling a lone beach-walker, "Get off the beach!"

Over in Berkeley, police had blocked off access to the Berkeley Marina, and Alameda County Emergency Services put out a warning as of 8:10 a.m. telling everyone in the marina to get off their boats and off of docks as well.

We'll update this post if and when more surges are evident from the tsunami.

Top image via Tim Cattera Photo