Powerful Magnitude 6.7 Gulf of California earthquake – P- and S-Wave seismograms

Though we included a live seismogram in one of our supporting articles, as the time passes the waves from the Gulf of California earthquake will disappear.
To avoid total erasing of this event, please find below the static seismogram from this M 6.7 earthquake.

Clicking on the image will lead you to the seismicnet website where seismograph builders are publishing their seismograms and their questions and answers.

An earthquake has always a P- and and S-wave, P being the first noticed, mostly seconds before the main tremor.

To understand P- and S-waves better, here is the wikipedia describing information (clicking on the link will give even more specialist details) :

P-waves are type of elastic wave, also called seismic waves, that can travel through gases (as sound waves), solids and liquids, including the Earth. P-waves are produced by earthquakes and recorded by seismometers. The name P-wave stands either for primary wave, as it has the highest velocity and is therefore the first to be recorded.

The S-wave, secondary wave or shear wave is one of the two main types of elastic body waves, so named because they move through the body of an object, unlike surface waves.
The S-wave move as a shear or transverse wave, so motion is perpendicular to the direction of wave propagation: S-waves, like waves in a rope, as opposed to waves moving through a slinky, the P-wave. The wave moves through elastic media, and the main restoring force comes from shear effects.


Western Mexican states hit by multiple aftershocks and earthquakes

The road runs the entire length of the Baja Ca...

Baja California Peninsula - Image via Wikipedia

The Mexican western states of Sonora, Baja California, Nayarit and Chiapas have been hit the last 24 hours by multiple earthquakes and aftershocks.
Everything seems to be moving and more tectonic movements may be expected.
4 different main areas can be defined.
a) The waters of the Gulf of California
With an epicenter in the coastal waters and a limited magnitude these earthquake can be categorized as safe.
b) The Sonora desert
The greater area of the massive M 7.2 earthquake from  April 4.  The epicenter of this earthquake was located more to the north in de border area between Mexico and the United States. Most of the aftershocks have an epicenter in unpopulated (beautiful!) desert areas.
c) The subduction zone of the Islas Marias islands
Active since a couple of weeks in various places and more or less in the greater Puerto Vallarta, Manzanilla zone.
Potentially dangerous if a shallow earthquake would strike nearer to the coastline.
d) Chiapas province
Regular (mostly deep) earthquakes with Magnitudes of +5. Harmless because of the depth of the hypocenter.

Overview of the  M +4 earthquakes from the last 24 hours (most recent above) (All times in UTC)

M 4.2      2010/09/15 08:21    Depth 10.0 km GULF OF CALIFORNIA
Third shock 8 seconds after the M 4.4 shock, in the middle of the peninsula

M 4.4      2010/09/15 08:13    Depth 10.0 km
Second shock only 2 minutes later, but under the peninsula

M 4.4      2010/09/15 06:46    Depth 10.0 km GULF OF CALIFORNIA
Light earthquake in the coastal waters of the Baja California peninsula. The whole area is very active the last couple of days.

M 4.7      2010/09/15 06:09    Depth 0.4 km     BAJA CALIFORNIA, MEXICO
Please also read the detailed page of this earthquake – Click here

M 5.1      2010/09/15 06:05    Depth 96.1 km CHIAPAS, MEXICO

Moderate but fairly deep and harmless earthquake near San Juan Custepeque , Chiapas Mexico

M 5.9      2010/09/14 23:32    Depth 36.0 km     ISLAS MARIAS REGION, NAYARIT, MEXICO
Click on this link for an extensive earthquake report

M 5.0      2010/09/14 10:52     Depth 10.0 km     BAJA CALIFORNIA, MEXICO
Click on this link for an extensive earthquake report

Heavy Aftershock in Baja California and the USA – Mexico border region

Mexicali at night

Mexicali at night - Image via Wikipedia

Earthquake Report comment :
The powerful aftershock occurred in the middle of the night.
The epicenter of this aftershock (earthquake) is in the same area than the M 7.2 main shock from April 4, 2010. Since that date a number of sometimes very powerful aftershocks have been hammering the border area.
Earthquake report does not think that there will be a lot of damage or injuries as people in this area have very strong building rules and have witnessed much stronger earthquakes the last few months.
Maximum shaking will be moderate to strong in the unpopulated epicenter area. Weak to light in the greater region.
Inhabitants of Tijuana and San Diego will have merely slept through it, with only light sleepers as witnesses from this aftershock.
Mercalli Intensities felt in various towns (in line with our predictions) :
Guadalupe Victoria : V (Moderate)
Greater Mexicali area : III (Weak to light)
San Diego and Tijuana : II to III (Weak)
The current epicenter is less than 20 km away from the April 4 earthquake epicenter and will probably be coming from the same fault line.
Click here for a picture of the sand dunes of the Laguna Salada landscape, extraordinary beautiful!. The Laguna Salada is part of the Yuha desert, where the earthquake epicenter is located.

Most important Earthquake Data:
Magnitude :  Ml 5.4
Tuesday, September 14, 2010 at 03:52:17 AM at epicenter
Depth (Hypocenter) : 11.5  km
Geo-location(s) (after recalculation) :
60 km (35 miles) SW of San Luis Rio Colorado, Sonora, Mexico
80 km (50 miles) SSE of Mexicali, Baja California, Mexico
95 km (60 miles) SSE of El Centro, California

Links to important maps
USGS Did You Feel It Map

Google satellite map of the area showing the kind of terrain the earthquake took place
USGS Shaking map

USGS Pager map

Seismograph of the event on nearby stations

QuakeSOS has been developed to help actively people who are caught in an earthquake + delivers "Earthquake Report" information on your iPhoneQuakeSOS is a FREE iPhone application developed by Armand Vervaeck, the creator and main contributor to Earthquake Report. The Application simplifies immediate group communication to friends and family members (with your exact GPS location) and is constantly feeding the users with “Earthquake Report” news. Together with your own family and friends, QuakeSOS will be your closest earthquake friend.

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