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    8.0 Earthquake Generated A Tsunami Between Santa Cruz Islands And Solomon Islands
    By Bente Lilja Bye | February 6th 2013 01:09 PM | 3 comments | Print | E-mail | Track Comments
    About Bente Lilja

    Earth science expert and astrophysicist writes about Earth observation, geodesy, climate change, geohazards, water cycle and other science related...

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    Puh! Another big one. Earthquakes of magnitude 8.0 are big to put it mildly. Luckily it happened deeper in the crust than first anticipated and thus the resulting tsunami wasn't as devastating as it very well could have been. While writing this 5 people are reported dead, but I am not so sure about the source of that information (only from news media).

    The Solomon islands in the Pacific Ocean are situated right smack on the Ring of Fire - a 'ring' formed by tectonic plates meeting and rubbing up against each other. Along the Ring of Fire there is a lot going on in terms of earthquakes and volcanic eruptions easily spotted on maps with historic data of tectonic activity.

    Ring of Fire - historic map of seismic activity in the Pacific/Australia
    The local part of the Ring of Fire is quite evident in this map. Credit: USGS/Benz H.M., Herman, Matthew, Tarr, A.C., Hayes, G.P., Furlong, K.P., Villasenor, Antonio, Dart, R.L., and Rhea, Susan, 2011, Seismicity of the Earth 1900–2010 Australia plate and vicinity: U.S. Geological Survey Open-File Report 2010–1083-G, scale 1:15,000,000.


    A tsunami warning was issued by the Pacific Ocean Tsunami Warning Center, a warning that is now cancelled. If you wonder how those look like you can see the real thing here:

    First confirmation of a tsunami issued by PTWC.

    Location of the Santa Cruz Islands earthquake
    If you are unfamiliar with the Salomon Islands or the Santa Cruz Islands in the Pacific, this map should give you a better geographical feel for it (the star no 1). Credit: IRIS

    Seismic array showing the Salomon qearthquake signal in the US
    The USArray picking up seismic signals from around the world. If you want to see something really cool you can go here and make sure you watch the videos. You will clearly see how the seismic waves travels through the North America continent. Credit: IRIS/Earthscope

    If you are interested in knowing more about tsunami warning systems you can get a good overview of the basic elements in a warning system by reading The Haiti Earthquake: Science, Early Warning and Mitigation.  In addition to the sensors picking up the earthquake signals, a tsunami early warning system also include tide gauges and buoys picking up the resulting wave signals. These signals is fed in to wave propagation models verifying the most likely wave distribution as the tsunami reaches land. Very simply said, that is.

    The tricky parts are estimation of the initial signals and data about shore conditions. The location, size of earthquake, particularly for the big ones, depth etc. are essential for picking the right wave model. The next tricky part is information about the  shore area such as bathymetry and topography of the land as this is important for detailed local estimations of where the wave will hit. You'll find more about these elements in Japan Tohoku earthquake and tsunami warnings - reading the signals I.

    Further recommended reading:

    IRIS - Incorporated Research Institutions for seismology
    USGS Geologic Hazards Science Center
    Pacific Tsunami Warning Center

    Comments

    rholley
    Here is a link to a larger map of the Solomon Islands:

    http://upload.wikimedia.org/wikipedia/commons/5/50/Solomon_Islands_1989.jpg

    On this map one can see that the capital of the Solomon Islands, Honiara, is on Guadalcanal, where a fierce battle was fought 1942–3.
    Robert H. Olley / Quondam Physics Department / University of Reading / England
    Stellare
    Thank you Robert!
    A much prettier map. I love the name of the Solomon Islands capital: Honiara! :-)
    Bente Lilja Bye is the author of Lilja - A bouquet of stories about the Earth
    Stellare
    If you are interested in learning more about earthquakes and the Ring of Fire you can watch 1 or more of the videos over at A Green Space - A Green Earth on Astrocast.TV.
    Bente Lilja Bye is the author of Lilja - A bouquet of stories about the Earth