Environment & Science

Tsunami advisory canceled for California (updated)

A tsunami advisory for the California coast has resulted in warnings of riptides and dangerous waters.
A tsunami advisory for the California coast has resulted in warnings of riptides and dangerous waters.
screengrab from NBC4

An 8.3 magnitude earthquake that struck off the coast of Chile left at least three people dead and raised concerns that areas along the Pacific — including Hawaii and the Californian coast — could see strong swells from the quake. California's coast saw a slight surge and powerful currents.

Updates: 

Update 1:41 p.m. Tsunami advisory canceled for California

The National Tsunami Warning Center has canceled a tsunami advisory for a 300-mile stretch of California's coast.

The advisory had applied to the coast from San Onofre State Beach, 45 miles southeast of Los Angeles, up to Ragged Point, 50 miles northwest of San Luis Obispo.

The warning center said Thursday that the tsunami generated after an magnitude-8.3 earthquake in the Pacific Ocean off Chile no longer poses a threat.

The center says, however, that some areas may see small sea level changes and surges.

The tsunami was recorded from San Diego to Alaska but only reached the center's advisory level for part of California.

-AP

Update 12:53 p.m. California coastal waters surge morning after Chile earthquake

A slight ocean surge and powerful currents were reported at points along the entire coast of California as a very small tsunami arrived early Thursday following a magnitude-8.3 earthquake that hit off the coast of Chile, scientists and local officials said.

Swimmers and surfers were warned of strong currents and urged to stay out of the water.

Ventura Harbor experienced a 1.1-foot tsunami, while 0.4 foot heights were reported in San Diego to the south and 0.8 foot heights were seen at Crescent City near the Oregon border, according to the National Tsunami Warning Center. Los Angeles-area beaches and harbor saw water level heights around a half-foot.

Boats were bobbing in Ventura Harbor, said harbormaster John Higgins.

"You'll see slow-moving streams coming in and going out, and at times the two converge upon each other and it creates turbulent water movement," he said.

The activity was "completely manageable" and not expected to have damaging effects, Higgins said.

The surge was expected to continue for several hours, with wave cycles every 20 minutes and heights topping out at around one foot, said Paul Whitmore, the tsunami center's director in Palmer, Alaska.

"It doesn't sound like much but even a very small tsunami has a lot of power," he said.

Orange County beaches, harbors, piers and marinas were reopened at 6 a.m., but swimmers and boaters were warned that strong currents could continue.

A tsunami advisory was in effect through at least early afternoon for a 300-mile stretch from south Orange County to Ragged Point about 50 miles northwest of San Luis Obispo. However, tsunami activity was reported well outside of the advisory territory — in Oregon, British Columbia and as far north as Alaska, where water heights of .6 foot were reported at King Cove.

A tsunami advisory falls short of a tsunami warning, and waves inundating the land were not expected. No evacuations were ordered.

AP

Thursday 7:10 a.m. Tsunami advisory: ‘Be extra cautious’ due to riptides 

Officials continue to warn Thursday that though the tsunami advisory issued for the California coast has resulted in waves small in appearance, danger is still present for boaters and people near the beaches.

“Even though this doesn’t have the classic visual of a tsunami of a big wave this is a huge volume of energy and in the marina this time of morning you have standup paddle boarders, rowers, charter fishermen … and the currents they’re used to and the weather behavior they’re used to is not what they’re going to see today,” L.A. County director of communications David Sommers told KPCC shortly before 6 a.m.

No L.A. County beaches are closed, though lifeguards will be on the beaches starting at 6 a.m.

“Number one thing between now and next high tide around noon is be extra cautious,” said Sommers. “It looks calm on the surface but there’s a lot of action under water, a lot of riptides. Think twice about going in.”

https://twitter.com/NWSLosAngeles/status/644418513214398464

All Orange County beaches are open, said L.A. County spokesman Bob Spencer, and as of 6 a.m., all beaches in the City of Seal Beach and the pier have been reopened, according to a Seal Beach Police Department statement.

Carol Baker with L.A. County Department of Beaches and Harbors echoed Sommers’ concerns. She said officials can’t stop people from going out to the water, but people should know that changes in swells are still possible.

She added that it might be safer to be on a docked boat instead of on a dock, because a boat properly docked with slack on the tethered rope has some give against the force of waves.

“There’s a lot of energy, you may not actually see a wave because we have a break water but there is a lot of energy behind the kind of force of a tsunami,” Baker told NBC4.  

- KPCC Staff

Update 8:14 p.m.: Tsunami advisory issued for California coast 

A tsunami advisory has been issued for a 300-mile stretch of the California coast after a powerful magnitude-8.3 earthquake hit off the coast of Chile.

Areas of the California coast outlined in yellow are under advisory of a tsunami after an 8.3M earthquake struck Chile on Wednesday, September 16, 2015. Courtesy NTWC.

The Pacific Tsunami Warning Center issued the advisory Wednesday night for an area stretching from the southern end of Orange County to Ragged Point about 50 miles northwest of San Luis Obispo.

A tsunami advisory falls short of a tsunami warning, and waves inundating the land are not expected.

It is expected to bring strong currents and dangerous waves to those in or very near the water, and the current could stay powerful for several hours.

The effects are expected to be first felt in Orange County at about 4:45 a.m. Pacific time Thursday, with areas further north feeling the effects in the following minutes.

Officials from the National Tsunami Warning Center told KPCC they're advising Southern Californians to stay out of the water and off the beach early tomorrow morning. 

The center told the station that the quake could cause swells of between 1 and 2 feet, enough to cause damage to boats and other structures at area marinas and to generate strong riptides. 

"We advise nobody should be in the water or near the beach," NTWC spokesman Paul Huang told KPCC, adding that waves could become slow and overwhelming, "like a flash flood."

This story has been updated.