Tsunami Advisory Ends; 1.2 Ft Rise in Sea Level Reported At Kahului Harbor 9/29/09

Image Courtesy USGS

The Tsunami Advisory for Hawaii has ended.

Maui Mayor Charmaine Tavares expressed appreciation for readiness in Hawaii, but sadness over the effects near the quake’s epicenter off of the Samoan Islands.

“I appreciate the emergency readiness of our partnering state and federal agencies. Their efforts are as valuable as the efforts of our citizens who take steps to be prepared before a disaster happens,” Tavares said.

“While we’ve averted a natural disaster, we’re saddened by the loss of life caused by the earthquake and tsunami in Samoa and American Samoa. They, along with our Filipino community who are struggling with the destruction created by this past weekend’s Tropical Storm Ketsana in the northern part of the Philippines, need our support and prayers,” said Mayor Tavares.

This will be the final message issued for this event, unless additional data is received.

(Updated @ 7:01 p.m. HST Tuesday, September 29, 2009)

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A tsunami advisory remains in effect until 7 o’clock tonight (Tuesday, September 29, 2009).  The effects of the lingering Advisory have been seen in the form of sea level changes on Maui.  The Maui County Civil Defense Agency reported a 1.2 foot rise in the ocean level at 3:09 p.m.  That was the second highest wave activity in Hawaii associated with the 8.3 earthquake that struck off the Samoan Islands this morning.  The largest wave activity in Hawaii was a 1.5 foot rise recorded at 3 p.m. on Oahu’s Haleiwa shore.  A nearly one foot sea level rise was also reported at Waianae on Oahu.  In addition to the sea rises, there was also a one foot drop or recession in the sea level reported at Kahului Harbor before 3 p.m.  While these waves are not expected to cause any significant coastal flooding, they can result in sea level changes, strong currents and hazardous conditions. Officials with the Civil Defense Agency continue to advise the public to exercise caution.  The tsunami Advisory is expected to expire at 7 p.m.

(Updated at 5:45 p.m. HST Tuesday, September 29, 2009)

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(Updated @4:20 p.m.)

The Tsunami Advisory will continue for the State of Hawaii until 7 p.m. HST.  While waves are not expected to cause any significant coastal flooding, they can produce small changes of sea level at the coast and strong or unusual currents that can be a hazard to swimmers, boaters and beachgoers.  The first effects were seen shortly after 1 p.m. , with a 1.2 foot rise in the ocean level reported at Kahului Harbor at 3:09 p.m.  Wave action can continue for several hours after the initial wave, and the first wave is often not the largest.

Pre-recorded advisories and notifications are available 24-hours a day on the Maui County Automated Information System (AIS) by calling 986-1200.

Please refer to the telephone book yellow section for preparedness information and evacuation areas.

MEASUREMENTS OR REPORTS OF TSUNAMI WAVE ACTIVITY

GAUGE LOCATION        LAT   LON    TIME        AMPL         PER

——————-  —– ——  —–  —————  —–

KAWAIHAE HAWAII      20.0N 155.8W  2:38 p  0.18M /  0.6FT  10MIN

KAPOHO HAWAII        19.5N 154.8W  2:42 p  0.14M /  0.5FT  08MIN

HONOLULU OAHU        21.3N 157.9W  3:08 p  0.16M /  0.5FT  10MIN

WAIANAE OAHU         21.4N 158.2W  2:25 p  0.26M /  0.9FT  12MIN

HALEIWA OAHU         21.6N 158.1W  3:00 p  0.46M /  1.5FT  08MIN

HILO HAWAII          19.7N 155.1W  2:12 p  0.16M /  0.5FT  18MIN

KAUMALAPAU LANAI     20.8N 157.0W  2:39 p  0.12M /  0.4FT  14MIN

MOKUOLOE OAHU        21.4N 157.8W  2:49 p  0.02M /  0.1FT  18MIN

KAHULUI MAUI         20.9N 156.5W  3:09 p  0.36M /  1.2FT  16MIN

NAWILIWILI KAUAI     22.0N 159.4W  3:08 p  0.22M /  0.7FT  08MIN

(Updated @4:20 p.m.)

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(Posted by Wendy Osher; Updated @ 3 p.m. HST 9/29/09)

The effects of a lingering Tsunami Advisory have been seen in the form of sea level changes on Maui.  Aquatics officials reported a one foot drop in the sea level at Kahului Harbor twice over a two hour period.  The drops were reported after 1 p.m. when harbor surges and ocean currents were projected to begin affecting the Hawaiian Islands.  This following a large 8.3 earthquake off the Samoa Islands this morning.  Officials with the Civil Defense Agency continue to advise the public to be cautions of sea level changes, strong currents and hazardous conditions.  A tsunami Warning was cancelled and replaced by a Tsunami Advisory at around 10:30 this morning.  The potential ocean impacts were expected to continue in the Hawaiian Islands until 4 o’clock this afternoon.

(Posted by Wendy Osher; Updated @ 3 p.m. HST 9/29/09)

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(Updated @ 10:45 a.m.)

The Pacific Tsunami Warning Center cancelled the Tsunami Watch for the state, putting an advisory in its place at around 10:23 this morning.

Based on all available data, a major tsunami is not expected to strike the State of Hawaii. However, sea level changes and strong currents may occur along the coast that could be a hazard to swimmers, boaters and beaches. All ocean recreation activities should remain cautious of tidal surge throughout the day.

High tide today will be approximately 2.0 – 2.4 feet between 1:00 p.m. to 1:45 p.m. at various points in Maui County. This will be on top of trade wind waves of 6 – 10 feet. People living in the inundation zone should be alert to ocean level changes.

The earliest impacts of possible sea level changes are estimated after 1 p.m. and can continue until 4 o’clock this afternoon.

INFORMATION:  Maui County Civil Defense will continue to monitor the situation.  Again, the Tsunami Watch was cancelled, and downgraded to an advisory which means sea level changes and strong currents may occur in coastal regions.

(Updated @ 10:45 a.m.)

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(Updated @ 10:25 a.m.)

A tsunami watch for Hawaii has been canceled, but an advisory is now in effect.  Based on All available data, a major tsunami is not expected to strike the state of Hawaii.  However sea level changes and strong currents may occur along the coast that could be a hazard to swimmers, boaters and beaches.  Therefore, a Tsunami Watch for Hawaii is cancelled, but an Advisory is in effect.

(Updated @ 10:25 a.m.)

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(Updated @ 8:15 a.m. HST)

A Tsunami Watch has been issued for the state of Hawaii following an 8.3 earthquake reported at 7:48 a.m. in the Samoa Islands Region.  The magnitude of the quake was upgraded from the initial 7.9 measurement released earlier this morning.  The quake was centered about 139 miles southwest of Pago Pago, American Samoa.

Based on all available data, a tsunami may have been generated by the earthquake.  An investigation is underway to determine if there is a threat to Hawaii.  In the meantime, there has been a watch issued for the state.

If tsunami waves impact Hawaii, the estimated earliest arrival time of the first wave would be at 1:11 p.m. on Tuesday September 29^th.  The Pacific Warning Center broke that down into regions of impact with Nawiliwili Harbor seeing the first effects at 1:11 p.m., Hilo at 1:14 p.m., and Honolulu at 1:15 p.m.  Again, this is a projection, and officials are still working to determine if a wave has been generated.

Actual arrival times may differ and the initial wave of a tsunami event may not be the largest.  A tsunami is a series of waves and the time between successive waves can be five minutes to one hour.

Again, this is a Tsunami Watch.  Officials are still investigating the event to determine if Hawaii will see any impacts.

We will update you with more information as it becomes available.

AN EARTHQUAKE HAS OCCURRED WITH THESE PRELIMINARY PARAMETERS

ORIGIN TIME – 0748 AM HST 29 SEP 2009

COORDINATES – 15.3 SOUTH  171.0 WEST

LOCATION    – SAMOA ISLANDS REGION

MAGNITUDE   – 7.9  MOMENT

Region:                            SAMOA ISLANDS REGION

Geographic coordinates:            15.556S, 172.302W

Magnitude:                        7.9 Mw

Depth:                            85 km

Universal Time (UTC):             29 Sep 2009  17:48:19

Time near the Epicenter:          29 Sep 2009  06:48:19

Local standard time in your area: 29 Sep 2009  07:48:19

Location with respect to nearby cities:

204 km (127 miles) SSW (197 degrees) of APIA, Samoa

224 km (139 miles) SW (230 degrees) of PAGO PAGO, American Samoa

388 km (241 miles) NNE (28 degrees) of Neiafu, Tonga

2432 km (1511 miles) W (272 degrees) of PAPEETE, Tahiti, French Polynesia

EVALUATION

BASED ON ALL AVAILABLE DATA A TSUNAMI MAY HAVE BEEN GENERATED BY  THIS EARTHQUAKE THAT COULD BE DESTRUCTIVE ON COASTAL AREAS EVEN  FAR FROM THE EPICENTER. AN INVESTIGATION IS UNDERWAY TO DETERMINE  IF THERE IS A TSUNAMI THREAT TO HAWAII.

IF TSUNAMI WAVES IMPACT HAWAII THE ESTIMATED EARLIEST ARRIVAL OF  THE FIRST TSUNAMI WAVE IS

0111 PM HST TUE 29 SEP 2009

LOCATION         FORECAST POINT     COORDINATES     ARRIVAL TIME

NAWILIWILI         22.0N 159.4W    1:11 p.m. HST 29 SEP

HILO               19.7N 155.1W    1:14 p.m. HST 29 SEP

HONOLULU           21.3N 157.9W    1:15 p.m. HST 29 SEP

ACTUAL ARRIVAL TIMES MAY DIFFER AND THE INITIAL WAVE MAY NOT BE THE LARGEST. A TSUNAMI IS A SERIES OF WAVES AND THE TIME BETWEEN SUCCESSIVE WAVES CAN BE FIVE MINUTES TO ONE HOUR.

(Updated @ 8:15 a.m. HST)