Hundreds Killed in 8.9 Japan Quake: Tsunami Advisory Continues in L.A. [UPDATED]

A powerful tsunami has claimed hundreds of lives on the northeast coast of Japan following the 8.9 magnitude mega-earthquake which struck at 9:46 p.m. Thursday L.A. time (2:46 p.m. Friday in Tokyo). The epicenter of the earthquake was located 80 miles off the eastern coast of Honshu at a depth of 15 miles triggering a massive tsunami with initial wave heights estimated between 13 and 23 feet, according to the USGS.

Please see our overnight coverage for photos, videos and more details of the initial devastation in Japan and tsunami watches, warnings and advisories for the California coast. This post reads as a liveblog, with the latest information timestamped at the top.

3:30 p.m.

• Gov. Brown has declared a state of emergency for four coastal counties in far-northern California (Humboldt, Del Norte, San Mateo, Santa Cruz).
• Crescent City Harbor in Del Norte county is "destroyed," according to the LA Times
• Japan declares its first-ever emergency at a nuke plant, thousands evacuated but still no radiation leak.
• Orange County beaches have been reopened with the exception of Huntington and Seal beaches, which are expected to reopen at 4 p.m., according to CNN
• Local non-profits are mobilizing to support quake and tsunami victims in Japan, reports KPCC
• Discovery's Science Channel is already planning an in-depth documentary on the earthquake and tsunami. Too soon? Apparently not. "'Anatomy of a Disaster' will depict a race against time, from the first wave to hit Sendai, to acts of incredible heroism still yet to occur," Discovery Channel president Clark Bunting told the Hollywood Reporter
• Kobe's parents are in Japan but are safe, in fact his dad today agreed to return to LA as an assistant coach for the Sparks of the WNBA.

12:30 p.m.One man may have been swept out to sea after taking pictures of the approaching waves near Crescent City, CA. The AP reports:

An L.A. County Search and Rescue team has been deployed to Japan where the death toll from Friday's 8.9 magnitude earthquake and devastating tsunami is expected to rise. At least one nuclear reactor "cannot be cooled down" and 3,000 have been evacuated, although reportedly there is no risk of radiation leaking, according to Kyodo News. A cruise ship and bullet train are also missing, reported the Daily Mail.

A tsunami advisory remains in effect for the California Coast south of Point Concepcion (near Santa Barbara). A tsunami warning remains in effect for points north although it appears the most damaging waves have passed.

The latest bulletin from the National Weather service notes wave amplifications around 11 a.m. at between one and three feet between San Diego and Santa Monica.

11:30 a.m.Earthquakes continue to rattle Japan. The latest of dozens of strong aftershocks measured greater than 6 in magnitude. Google has established an online crisis center and people finder for the event.

Japan has officially requested assistance and the U.S. has ships and aircraft carriers on the way, according to the Obama administration.

Here's the latest report from Al Jazeera English via this liveblog:

10:00 a.m.We're still here! Be glad you were prepared, some day we may not have hours of advance warning. The state Department of Conservation has tips for tsunami preparedness here. Tokyo is still at a standstill (of course it is only 3:30 a.m. Saturday there). Some amazing video came in overnight. Check it out at YouTube's CitizenTube. This gigantic photoessay at BoingBoing is also worth a look.

Some Hawaii beaches received significant surges but no damage has been reported. The same cannot be said in Northern California where damage was reported at Santa Cruz Harbor.

Dodgers pitcher Hiroki Kuroda, one of 14 Japanese baseball players on 2010 Major League rosters, still hasn't heard from his brother.

8:00 a.m.It's now more than 10 hours since a massive 8.9-magnitude earthquake off the northeastern coast of Japan spawned a tsunami. The first effects of the tsunami are now being seen in Northern California. By 9:00 a.m. there will be a slight increase in the swell in Southern California. The waves may not be huge, but if you've ever experienced the undertow -- imagine a series of waves coming ashore at speeds up to 500 mph. In other words: no need to panic, just don't go to the beach.

7:00 a.m. The entire Southern California coast is under a tsunami advisory (a tsunami warning has been issued for coastal areas north of Point Concepcion). Malibu and Newport beaches are closed this morning as a precaution, according to police. San Diego County beaches are also closed. While the waves are not expected to be huge, a strong current is the concern. Tsunamis can travel at speeds as high as 500 mph. The first effects of the tsunami are expected around 8:30 a.m. L.A. time.

The California coast is expecting a few swells from the massive tsunami with waves of 3 to 7 feet expected, according to the latest estimates from the Pacific Tsunami Warning Center. The largest projected to to the north and Crescent City near the Oregon border, where eleven were killed following a 1964 Alaskan quake.

The Red Cross in Japan is accepting donations and George Takei seeded the following tweet: "Today we are all Japanese. Give $10 to help. Text REDCROSS to 90999, or click http://ow.ly/4ctzx."

6:50 a.m. Much of Hawaii has experienced two waves from the tsunami over the past hour as it heads toward the U.S. Pacific Coast. The initial wave, around 6 a.m. L.A. time (3 a.m. Honolulu) was estimated at just under 3 feet and the second wave, 30 minutes later, at up to 6 feet. No damage has been reported.

6:00 a.m. The latest reports from the AP show a significant bump up in casualties, with 200 to 300 bodies reportedly washed ashore near the city of Sendai in northeastern Japan, according to police. Another 88 were confirmed killed and at least 349 were missing. Japan is still under cover of darkness (the initial quake occurred at 2:46 p.m. Tokyo time and it is now 11:00 p.m.). The death toll was likely to continue climbing given the scale of the disaster.

We are currently monitoring the situation via multiple media sources including local radio, TV, and CNN's four live streams.