Double 7.0+ magnitude earthquakes shake South Pacific island of Vanuatu

August 20, 2011VANUATU – A powerful magnitude 7.5  (7.1 downgrade USGS) earthquake struck off the Pacific island nation of Vanuatu, the U.S. Geological Survey reported Saturday. It said the quake, which struck at 3:55 a.m. local time on Sunday (12:55 p.m. EDT on Saturday), was centered 38 miles southwest of the town of Port-Vila and was quite shallow, at a depth of 25.2 miles. The Pacific Tsunami Warning Center said the major quake had not triggered a Pacific-wide tsunami but said: “Earthquakes of this size sometimes generate local tsunamis that can be destructive along coasts located within a hundred kilometers (80 miles) of the earthquake epicenter.” There was no immediate information of any damage or casualties, but when on land quakes of this magnitude can cause widespread and heavy damage. The quake was followed by a weaker aftershock of magnitude 5.9 some 20 minutes later. The Vanuatu archipelago is located on the so-called “Ring of Fire,” one of the most seismically active regions in the world. Port-Vila is the capital of Vanuatu and has an estimated population of 40,000 people. After a flurry of aftershocks, a second 7.0 earthquake stuck the same region at a depth of 2 km.  –Reuters              
See: String of moderate quakes shake globe
This entry was posted in Earth Changes, Earth Watch, High-risk potential hazard zone, Potential Earthchange hotspot, Seismic tremors, Strange high tides & freak waves, Volcano Watch. Bookmark the permalink.

20 Responses to Double 7.0+ magnitude earthquakes shake South Pacific island of Vanuatu

  1. Raven says:

    MAP 5.1 2011/08/20 17:44:27 -18.770 167.924 9.5 VANUATU
    MAP 4.8 2011/08/20 17:28:52 -20.736 -177.528 371.2 FIJI REGION
    MAP 5.9 2011/08/20 17:13:07 -18.287 168.062 37.3 VANUATU
    MAP 5.6 2011/08/20 17:11:36 -18.289 167.755 40.9 VANUATU
    MAP 5.0 2011/08/20 17:08:37 -31.402 -178.702 227.9 KERMADEC ISLANDS REGION
    MAP 7.5 2011/08/20 16:55:03 -18.259 168.069 40.6 VANUATU


  2. Raven says:

    Magnitude 5.2 – VANUATU
    2011 August 20 18:02:00 UTC
    Another one Alvin


  3. luisport says:

    18:00 UTC : It will probably take a couple of hours before that we can have more information from this remote area in the world. We do say this on the basis of earlier similar earthquakes.

    17:58 UTC : If the tsunami waves will be 2 meters in reality (the predicted height is theoretical), than we can speak from a very severe tsunami on this location


  4. luisport says:

    2011-08-20 18:02:00.0
    28min ago 18.58 S 168.05 E 30 mb
    5.2 VANUATU 2011-08-20 18:27
    2011-08-20 17:44:33.0
    45min ago 18.84 S 168.04 E 60 mb
    5.0 VANUATU 2011-08-20 18:09
    2011-08-20 17:29:03.0
    1hr 17min ago 18.32 S 168.14 E 40 mb
    5.9 VANUATU 2011-08-20 17:30
    2011-08-20 17:11:35.6
    1hr 18min ago 18.29 S 167.75 E 41 M
    5.6 VANUATU 2011-08-20 17:36
    2011-08-20 17:08:28.3
    1hr 35min ago 18.34 S 168.16 E 30 Mw
    7.5 VANUATU


  5. They just had another big one, a 7.4. Still no tsunami advisory except for some localized ones. Could be another major swarm like in Japan?


  6. luisport says:

    Magnitude 7.0 – VANUATU
    2011 August 20 18:19:21 UTC

    Magnitude 7.0

    Saturday, August 20, 2011 at 18:19:21 UTC
    Sunday, August 21, 2011 at 05:19:21 AM at epicenter

    Location 18.343°S, 168.156°E
    Depth 2 km (1.2 miles) (poorly constrained)
    Region VANUATU

    68 km (42 miles) SSW (193°) from PORT-VILA, Vanuatu
    176 km (110 miles) NW (318°) from Isangel, Vanuatu
    331 km (206 miles) SSE (161°) from Santo (Luganville), Vanuatu
    1854 km (1152 miles) ENE (60°) from Brisbane, Australia

    Location Uncertainty horizontal +/- 14.7 km (9.1 miles); depth +/- 8 km (5.0 miles)
    Parameters NST= 97, Nph= 97, Dmin=449.7 km, Rmss=1.44 sec, Gp= 25°,
    M-type=regional moment magnitude (Mw), Version=6

    Magnitude: USGS NEIC (WDCS-D)
    Location: USGS NEIC (WDCS-D)


  7. Raven says:

    Ohhh dear Luisport….looks like we were up to the same thing 🙂


  8. luisport says:

    18:50 UTC : FELT Reports as received by from Vanuatu
    Vanuatu : Longues secousses. Piscine qui deborde. Long shaking + swimming pool which is overflowing. MMI V and MMI VI checked.
    Efate : Experienced severe quake at 5.30 approx – much stronger than 7.5 at 3.55 am MMI VIII checked (Severe shaking)

    18:50 UTC : A massive 7.0 aftershock has hit the same area. GDACS calculated tsunami heights based on a 7.4 magnitude. It was recalculated later to 7.0, which is a lot less. The aftershock was reported at a depth of 28.5 km. Click here for the epicenter of this massive aftershock.


  9. skywalker says:

    wow….2 quakes at 7.0 and 7.1 in the same place within hours of each other….and theres been loads of 5’s in this place for weeks now.

    surfs up dude


  10. luisport says:

    20:23 UTC : The Vanuatu Meteorological Service said tsunami waves of 1.05 meter (3.4 feet) arrived on the island of Efate less than an hour after the earthquake. It said there was no damage from the initial waves and has since cancelled the advisory.


  11. marie says:

    More and more birth pains showing up on the planet ushering the arrival of a new age for mankind. If only all would see it that way and get ready!


  12. Pagan says:

    I’ve been to Vanuatu, it’s basically just islands- very beautiful ones – but if a tsunami hits after these quakes, they will not stand a chance, much of it is on sea level.

    Lighting a candle for my friends in Vila.



  13. Shon says:

    I think it’s amazing that people forget their sixth grade geology lessons. All of this is cyclical and people are freaking out like it’s super strange stuff. The earth landmass has changed many times in its life. We are not the first humans to experience it, we’re not even as technologically advanced as the last lot! Marie, I doubt many humans will still be around to experience the new look Earth! With the NWO taking charge of the new Earth I don’t want to be around.


  14. Terry Thomas says:

    I did a little background check and they have been having these kinds of quakes here for years and with little Tsunami effect. One was like 35 meters and another smaller, as I recall. Do not know why some some cause bit Tsunamis and others don’t. Unless it is the location.


    • Correct me if I’m wrong, Alvin, but I believe that most tsunamis are caused by earthquakes are caused by thrust earthquakes, where part of the sea bed is lifted, therefore displacing the water. However, not all thrust quakes cause tsunamis or they cause tsunamis that are not noticeable.


      • Landslides, and strato-volcanic eruptions can produce tsunamis as was the case with the terrible tsunami unleashed by the eruption of Krakatoa in 1883 in Indonesia (see clip below), underwater volcanic eruptions can also produce tsunamis as would be the case with the Marsili volcanic complex off the coast of southern Italy but one of the most common causes happen to be the sudden thrusting of one slab of earth under another in a subduction zone due to a megathrust earthquake event.


      • Oh definitely, I apologize for not mentioning those. My mind was just on earthquakes since mega-thrust earthquakes are notorious for recent, terrible tsunamis. One landslide tsunami I remember hearing about is up in Alaska and one I am watching for and concerned about is the possibility of eruption or landslide on the Canary Islands, especially with all the rumbling that has been going on. A tsunami from there would be devastating to the East Coast. Krakatoa was an enormous tsunami which I believe was from the sudden and total explosion of the volcano. Talk about displacing water. And now Anak Krakatoa has been growing, but I haven’t heard anything about that one lately. Of course, with everything else going on, I could have missed it.

        Thank you Alvin and be blessed.



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