Tsunami waves in Hawaii smaller than expected

Tsunami Update | Technical details

Update: Tsunami waves in Hawaii smaller than expected

Surfersvillage Global Surf News, 28 October, 2012 : - - The first surges to hit Hawaii from the Canadian tsunami were smaller than expected. Measurements of the first surges to hit the islands varied from seven inches in Hanalei on Kauai to nearly two feet in Kahului, Maui. In Hilo, the wave that arrived at 10:34 p.m. measured just over eight inches in height. That was the earliest wave to hit the islands, according to the six gauge readings contained in a report issued by the Pacific Tsunami Warning Center.

State Civil Defense previously said the first effects of the tremor to arrive in Hawaii were expected at Kauai at around 10:28 p.m., with waves hitting Hilo about 30 minutes later. According to the report from the tsunami warning center, the wave hit Hanalei at 10:43 p.m., at Haleiwa on Oahu and Kahalui at 10:44 and at Waianae on Oahu’s leeward coast at 10:55 p.m.

Civil Defense officials were warning Hawaii residents to remain on alert as subsequent waves are often larger than the first one. Hawaii has been under a statewide tsunami warning since 7:09 p.m. as a result of the major earthquake that struck off the coast of Canada. Tsunami warning sirens sounded across most of Hawaii and people in inundation zones were urged to evacuate immediately.

On the Big Island, tsunami warning sirens sounded repeatedly in Kona but were delayed in Hilo. A 6:30 p.m. bulletin from Hawaii County Civil Defense said a tsunami warning was not in effect. That report said while a tsunami wasn’t generated, Hawaii could experience “small non-destructive sea level changes” as well as strong currents that could last several hours.

The magnitude 7.7 earthquake that generated the waves struck at 5:04 Hawaii time. The earthquake’s epicenter was in a seismically active area in the Queen Charlotte Islands off the coast of British Columbia. The tremor was initially measured at magnitude 7.1 but was later upgraded to a magnitude 7.7. It was followed by several aftershocks, including several minutes later with a magnitude of 5.8. The initial quake struck at a depth of 8.7 miles.

Early Report: Tsunami on way to Hawaii expected to hit 4.28 am, Oregon, California on alert

Surfersvillage Global Surf News, 28 October, 2012 : - - After a 7.7 Earthquake in Western Canada close to the Queen Charlotte Island Region a tsunami warning sirens have sounded the alarm as a tsunami was generated. The wave is on the way to Hawaii and is expected to hit at 22.28h HST, 4.28 am EST. The warning is issued for the entire State of Hawaii and all coastlines. Hawaii Civil Defense is posting updates and important information on http://www.scd.hawaii.gov. A tsunami watch is issued for Oregon and California.

Hawaii Civil Defense is currently warning residents and visitors by sirens. Local TV and radio station interrupted programs and are updating. Evacuation orders are issued. Police is directing traffic one way to evacuate Waikiki. Everyone in Waikiki should be on the 10th story or higher. No traffic is allowed into Waikiki at this time.

The highest waves are expected on the Northern Facing Shores of all islands. The situation may be specially critical for harbors on the Big Islands and Kapalui Harbor on Maui. The waves are expected to be 6 ft high. Waikiki is under an evacuation order, but East and South facing shores may be effected less. All entertainment venues in Waikiki are closed.

Latest indicators state waves may not be as high as originally estimated. Tsunamis in Japan and Indonesia had higher ratings. According to the Tsunami warning center, this is impossible to predict. The Pacific Tsunami Warning center expects not to clear warnings until several waves will be evaluated.

The Pacific Tsunami Warning Center in Ewa Beach is predicting wave heights of 3 to 6 feet in some locations. The biggest waves are expected in Hilo, Kahului, Haleiwa and Hanalei.

The quake in the Queen Charlotte Islands region occurred at 5:04 p.m. Hawaii time, the U.S. Geological Survey reported. The epicenter was 126 miles south-southwest of Prince Rupert, B.C., and 452 miles northwest of Vancouver. The National Weather Service issued a warning for coastal areas of British Columbia, southern Alaska, Northern California, Oregon and Washington state.

It says the warning area includes Craig and Sitka, Alaska.

The USGS reports the 7.7-magnitude quake was followed by 5.8 and 5.1-magnitude aftershocks.

www.scd.hawaii.gov
www.earthquake.usgs.gov

Source: Hawaii Civil Defense

Author: The Editors

Tags: Tsunami, Hawaii

Environment: Surfersvillage