8.8 Quake hits Chile

[rajncajn]

How far is that from the coast? isnt all teh islands volcanic mountains? I ahvent been there . . but I woudl assume that the topography would rise fairly quickly once you get off the beach?

 

Can anyone weigh in here? Cause a 8-16 foot wave is no joke . . . if the land slopes up right away that will mitigate damage . . .

Mom's house is 1500' elevation & they're still close enough to hear the waves at night. They're on the Big Island though & not all the islands are as mountainous and most of the larger towns are along the shoreline.

 

So it's "only" the big island Hawaii? I thought they were saying Hawaii ie meaning the chain. d'oh.

 

And it seems kinda weird that this would even be as significant as they say - I mean I realize 8.8 is a massive quake, but Hawaii is very damn far from Chile - looks like ~ 5/6000 miles-ish or more on a map glance. I know tsunamis build up, but eventually they'd start to subside over such long distances. Also apparently this thing will travel northwest...I wonder if that's due to currents or plate tectonics, or both, or.....

 

Guess I need to watch those weather report specials more.

It's every island in the South Pacific, but since we're watching US news & Hawaii is much more populated that is what you see. It is far, but it's such a large mass of water moving at such a high rate of speed it can do a ton of damage.

[BillyBalata]

CNN reporting first wave could hit any time.

[bushwacked]

Hearing the hypocenter was 22 miles below surface; that's going to end up saving a lot of lives and minimizing damage.

[bpwallace49]

Fox news is showing a long distance view of the waves in Oahu. There is nothing to provide scale so these waves could be the size of the Empire State building or tiny ripples. lunch time for breakfast?

[bushwacked]

Fox news is showing a long distance view of the waves in Oahu. There is nothing to provide scale so these waves could be the size of the Empire State building or tiny ripples. lunch time for breakfast?

 

 

Again, tsunamis generally aren't like giant tidal waves. It's the force and water mass that is typically a concern. The ones that caused the fatalities 6 years ago in Asia were about 15 feet high.

[bpwallace49]

Again, tsunamis generally aren't like giant tidal waves. It's the force and water mass that is typically a concern. The ones that caused the fatalities 6 years ago in Asia were about 15 feet high.

 

That is the point . . . there is a live feed, but no sense of scale. Why bother with a live feed then?

 

Very interesting interview with a geologist right now

[Ursa Majoris]

Again, tsunamis generally aren't like giant tidal waves. It's the force and water mass that is typically a concern. The ones that caused the fatalities 6 years ago in Asia were about 15 feet high.

Exactly. A tsunami may not even be visible in deep water but as the water gets shallower it rises up and the force compresses into a smaller area.

[cliaz]

It's a Tsunami warning not a biblical tidal wave warning.

 

The 2004 one was biblical in stature. Doesn't really matter, trillions of gallon of water only 3 feet with troughs miles long can wipe out everything in its path. Universally, people underestimate the power of water. It only takes five inches of fast moving water to move a truck.

 

So it's "only" the big island Hawaii? I thought they were saying Hawaii ie meaning the chain. d'oh.

 

And it seems kinda weird that this would even be as significant as they say - I mean I realize 8.8 is a massive quake, but Hawaii is very damn far from Chile - looks like ~ 5/6000 miles-ish or more on a map glance. I know tsunamis build up, but eventually they'd start to subside over such long distances. Also apparently this thing will travel northwest...I wonder if that's due to currents or plate tectonics, or both, or.....

 

Guess I need to watch those weather report specials more.

 

In US and PAC rim countries, when a warning is issued for Hawaii they are referring to the whole archipelago which is called, "The Hawaiian Archipelago" Your assessment of the size of the earthquake and the distance is a somewhat valid one. This earthquake was somewhat shallow in terms of EQs. For example, the 7.0 yesterday off the coast of Japan was 77 km which limited the shake factor and seismic wave intensity. Not to mention that area isn't a subduction zone but one where two plates are sliding by each other.

 

This earthquake (8.8) was shallow at 35 km and is on a subduction zone which means the plate coming off of Chile bulged up which has the potential to displace massive amounts of water much the same (in motion, not actual) as the 2004 one. Because of the specifics of the earthquake, location, magnitude, depth,etc, the initial models indicated an unacceptable range of variables which dictated the PAC rim and Hawaii alerts.

 

Peep the projected Tsunami projections for this earthquake: here

 

I'm tsunami-illiterate, but...

 

is a 2-3 foot wave really a big deal? I think we get bigger waves than that at the Jersey coast all the time?

 

It's not unless it is traveling about 80 mph when it hits the shore and the trough is a mile long.

 

That's what I thought - the Richter scale is logarithmic and gets exponentially more powerful with every step up. I cannot remember an earthquake that large.

 

The Richter scale has been updated recently (past few years) and now has the ability to measure the magnitude and the actual shake factor.

 

 

Here is my email alert from the USGS for today's earthquake:

 

 

 

Earthquake Details

Magnitude 8.8

Date-Time

 

* Saturday, February 27, 2010 at 06:34:14 UTC

* Saturday, February 27, 2010 at 03:34:14 AM at epicenter

* Time of Earthquake in other Time Zones

 

Location 35.846°S, 72.719°W

Depth 35 km (21.7 miles) set by location program

Region OFFSHORE MAULE, CHILE

Distances 100 km (60 miles) NNW of Chillan, Chile

105 km (65 miles) WSW of Talca, Chile

115 km (70 miles) NNE of Concepcion, Chile

325 km (200 miles) SW of SANTIAGO, Chile

Location Uncertainty horizontal +/- 7.2 km (4.5 miles); depth fixed by location program

Parameters NST=255, Nph=255, Dmin=988 km, Rmss=1.12 sec, Gp= 36°,

M-type=teleseismic moment magnitude (Mw), Version=7

Source

 

* USGS NEIC (WDCS-D)

 

Event ID us2010tfan

 

Tectonic Summary

 

This earthquake occurred at the boundary between the Nazca and South American tectonic plates. The two plates are converging at a rate of 80 mm per year. The earthquake occurred as thrust-faulting on the interface between the two plates, with the Nazca plate moving down and landward below the South American plate.

 

Coastal Chile has a history of very large earthquakes. Since 1973, there have been 13 events of magnitude 7.0 or greater. The February 27 shock originated about 230 km north of the source region of the magnitude 9.5 earthquake of May, 1960 – the largest earthquake worldwide in the last 200 years or more. This giant earthquake spawned a tsunami that engulfed the Pacific Ocean. An estimated 1600 lives were lost to the 1960 earthquake and tsunami in Chile, and the 1960 tsunami took another 200 lives among Japan, Hawaii, and the Philippines. Approximately 870 km to the north of the February 27 earthquake is the source region of the magnitude 8.5 earthquake of November, 1922. This great quake significantly impacted central Chile, killing several hundred people and causing severe property damage. The 1922 quake generated a 9-meter local tsunami that inundated the Chile coast near the town of Coquimbo; the tsunami also crossed the Pacific, washing away boats in Hilo harbor, Hawaii. The magnitude 8.8 earthquake of February 27, 2010 ruptured the portion of the South American subduction zone separating these two massive historical earthquakes.

 

A large vigorous aftershock sequence can be expected from this earthquake.

 

And my Tsunami alert email:

 

To: U.S. West Coast, Alaska, and British Columbia coastal regions, subscribers, FEMA, IAEM members

From: NOAA/NWS/West Coast and Alaska Tsunami Warning Center

Subject: Tsunami Advisory #16 issued 02/27/2010 at 1:47PM PST

 

A Tsunami Advisory is in effect which includes the coastal areas of California, Oregon, Washington, British Columbia and Alaska from the California-Mexico border to Attu, Alaska.

 

A Tsunami Advisory means that a tsunami capable of producing strong currents or waves dangerous to persons in or very near the water is imminent or expected. Significant, widespread inundation is not expected for areas under an advisory. Currents may be hazardous to swimmers, boats, and coastal structures and may continue for several hours after the initial wave arrival.

 

At 10:34 PM Pacific Standard Time on February 26, an earthquake with preliminary magnitude 8.8 occurred near the coast of central Chile . (Refer to the United States Geological Survey for official earthquake parameters.) This earthquake has generated a tsunami which could cause damage to coastal regions in a warning or advisory. Estimated tsunami arrival times and maps along with safety rules and other information can be found on the WCATWC web site.

 

A tsunami has been observed at the following sites:

 

Location Lat. Lon. Time Amplitude

------------------------ ----- ------ ------- -----------

 

Santa Monica CA 34.0N 118.5W 2021UTC 0.66M/2.2ft

Santa Barbara CA 34.4N 119.7W 2029UTC 0.43M/1.4ft

Monterey Harbor CA 36.6N 121.9W 2031UTC 0.28M/0.9ft

Los Angeles CA 33.7N 118.3W 2015UTC 0.41M/1.3ft

La Jolla CA 32.9N 117.3W 2048UTC 0.34M/1.1ft

Arena Cove CA 38.9N 123.7W 2046UTC 0.35M/1.2ft

San Diego CA0 32.7N 117.2W 2014UTC 0.42M/1.4ft

The tsunami is now impacting the U.S. California coast and has been

observed on several tide gages. Reports indicate that

navigational buoys in Ventura Harbor have been damaged. The

largest observed tide gage reading was recorded in Santa Monica,

CA. The tsunami is expected to continue to grow and be dangerous

for the next two to four hours.

 

Time - Time of measurement.

Amp. - Tsunami amplitudes are measured relative to normal sea level. It is NOT crest-to-trough wave height. Values are given in both meters (M) and feet (FT).

 

Tsunamis can be dangerous waves that are not survivable. Wave heights are amplified by irregular shoreline and are difficult to forecast. Tsunamis often appear as a strong surge and may be preceded by a receding water level. Mariners in water deeper than 600 feet should not be affected by a tsunami. Wave heights will increase rapidly as water shallows. Tsunamis are a series of ocean waves which can be dangerous for several hours after the initial wave arrival. DO NOT return to evacuated areas until an all clear is given by local civil authorities.

 

The Pacific Tsunami Warning Center in Ewa Beach, Hawaii will issue messages for Hawaii and other areas of the Pacific outside the states and provinces listed above.

.

 

You have to love technology and the ability to have a lot of information delivered instantly in these situations. I put our PAC rim datacenters on alert if they were within 20 miles of the coast or in or near flood plains. I engaged our POCs for the Southern Cali area and alerted them that we may need to enact some continuity prep procedures.

 

We have been experiencing an increase in large earthquakes the past 9 months.

[bushwacked]

The 2004 one was biblical in stature. Doesn't really matter, trillions of gallon of water only 3 feet with troughs miles long can wipe out everything in its path. Universally, people underestimate the power of water. It only takes five inches of fast moving water to move a truck.

 

Yes, power of water is underestimated indeed. My point was that a lot of people have a misconception about tsunamis; my thread was a response to the comment about evacuating the islands. In general, you get inland far enough and above sea level a bit, and you're going to be okay. Hawaii has some pretty decent topographical relief.

Edited February 28, 2010 by bushwacked

[cliaz]

Yes, power of water is underestimated indeed. My point was that a lot of people have a misconception about tsunamis; my thread was a response to the comment about evacuating the islands. In general, you get inland far enough and above sea level a bit, and you're going to be okay. Hawaii has some pretty decent topographical relief.

 

 

Gotcha. And correct, hawaii has fantastic landscapes that are perfect for mitigating the effects of a wave. It's all the people who want to stand down on the beaches and watch the waves come in that will be the issue

[muck]

When are the waves supposed to hit? Or did they hit already?

 

...just curious...

[Big John]

When are the waves supposed to hit? Or did they hit already?

 

...just curious...

They hit already. Thankfully it was a minor hit.

[bushwacked]

Gotcha. And correct, hawaii has fantastic landscapes that are perfect for mitigating the effects of a wave. It's all the people who want to stand down on the beaches and watch the waves come in that will be the issue

 

I have a Tsunami escape route that leads to my backyard.