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.

Christchurch Earthquake Damage Map with ‘damage and testimonies’

Earthquake-Report.com is always in for “added value” articles from local publishers.
We came across a fantastic initiative from “The Press – Stuff.co.nzwho had the idea of bundling testimonies from people living in the earthquake area on a google map. With colored buttons viewers can click on each of the buttons and read the story behind the button.

Most damage seem to have occurred in the old city center of Christchurch, although other parts of the area were also hurt.

If you click on the map, you are linked to the big interactive earthquake map from the publisher.
Congratulations from Earthquake-Report.com for this great initiative.

Improved New Zealand tsunami monitoring system in place

The likely impact of tsunami on New Zealand’s coastline is now better understood following the completion of a major project to install sea level monitoring devices.

Sea level gauges have been installed at 17 sites around New Zealand and offshore islands. Pressure sensors at the gauges measure any significant change in the sea level, with data being transmitted in real time to GNS Science’s GeoNet data management centre.

GNS Science assesses the data and advises the Ministry of Civil Defence and Emergency Management (MCDEM) about the level of threat posed by tsunami. MCDEM is responsible for managing the response to any threat, which may include issuing public warnings.

The tsunami network project, led by Land Information New Zealand (LINZ), now forms an important component of a wider tsunami monitoring system for New Zealand and across the Pacific.

Graeme Blick, Chief Geodesist at LINZ, said the project was initiated following the devastating Boxing Day 2004 tsunami in the Indian Ocean, caused by a 9.3 magnitude earthquake off the coast of Sumatra. Waves up to 1 metre in height were recorded at sites around New Zealand 18 to 25 hours after the earthquake occurred, highlighting New Zealand’s vulnerability to tsunami.

Mr Blick said the installation took five years to complete, and was made more challenging by the rough and rugged environment in which the sea level gauges were installed, and the long process of obtaining approvals and consents. The last sensor was installed in July 2010.

Agencies involved included GNS Science, MCDEM, NIWA, MORST, Waikato University and consultancy firm URS, as well as Australian agencies involved in the development of a similar network there.

“The fact the network was completed on time and within budget is testament to the cooperative effort that went in to the project,” Mr Blick said.

GNS Science worked closely with LINZ, providing technical expertise throughout the installation phase. Dr Ken Gledhill, Geohazards Monitoring Manager for GNS Science, said the project was a great example of collaboration across the public and private sectors.

Over the past 150 years, New Zealand has experienced about 10 tsunami higher than 5 metres, which can put people and property at risk. Large earthquakes can have devastating effects, both on land and water, Dr Gledhill said, as the people of Christchurch can testify.

“Since installation of the network began in 2005, several large regional and distant earthquakes have generated tsunami,” he said. “The network has successfully detected these, including the 2009 Samoan and 2010 Chilean earthquakes and the resulting waves that hit our coastline.” (Source : GNS Science)

Picture “Sourced from LINZ. Crown Copyright reserved.”

Powerful but deep earthquake in New Zealand Waikato

A look down one of the main streets of Tokoroa...

Tokoroa - Image via Wikipedia

Earthquake Report comment :
855 ‘Felt’ reports came in with GNS Science for this powerful but deep earthquake.
The epicenter was located near Tokoroa  in the Waikato district, only approx. 30 km from Rotoroa, well known by tourists.
Most of the people have reported a MM IV = light shaking.
Based on the 200 km depth of the hypocenter these reports match. Also because of the depth, the earthquake was felt in a very wide range around the epicenter the same way.

Most important Earthquake Data:
Magnitude : M 5.6
Sep 24 2010 at 7:47 pm at epicenter
Depth (Hypocenter) : 200 km
Geo-location(s) :
10 km east of Tokoroa

Links to important maps
Geonet Did You Feel It Map
Google satellite map of the area showing the kind of terrain the earthquake took place
Geonet Shaking map
The nearest GNS Science Pawanui Live Seismograph

* GDACS (Global Disaster Alert and Coordination System) provides near real-time alerts about natural disasters around the world. GDACS is a Joint Initiative of the United Nations and the European Commission

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.

In memory of the victims of September 6, 19XX – Turkey, Papua New Guinea and Italy

M 6.7    06-09-1975    Turkey    – Depth 39.6 km – killing 2370 people
Google satellite map of the earthquake area

This destructive earthquake struck eastern Turkey. It was centered in the Diyarbakir Province. The shock reportedly killed more than 2,000, injured 3,400, and caused extensive property damage in the Lice area. The earthquake struck at lunch time when most people were inside and the children were home from school. Reports indicated that most schools were not seriously damaged. The districts reported hardest hit were Hazro, Hani, Kulp, and Lice, which was almost completely destroyed. Many strong aftershocks followed the main shock, causing the collapse of already partly damaged homes, and keeping the surviving residents quite frightened.

M 4.3    06-09-1988    Papua New Guinea  –  Depth 0 km – killing 74 people
Google satellite map of the earthquake area

About 74 people killed and many houses destroyed by a massive landslide near Kaiapit. The P-waves recorded from this event appear to have been generated by the landslide itself.

M 5.9    06-09-2002    Italy    – Depth 13 km – killing 2 people
Google satellite map of the earthquake area

Two people died from heart attacks, twenty injured and several buildings damaged in the Palermo area. Also felt at Agrigento, Caltanissetta, Catania, Enna, Messina and Trapani.

“In memory of” is highlighting deadly earthquakes of the past.
People have forgotten a lot of these human tragedies.
We @ Earthquake Report are hopeful that people in these countries and cities will learn from their history and will make sure that they are building Earthquake Proof houses and that they know what to do when the earth will be shaking again.

QuakeSOS Twitter linkWhat do we offer on our @QuakeSOS twitter link ? :
– The titles of, and links to the in-depth articles of Earthquake-report.com
– Automatic alerts of all important earthquakes in almost real time as they occur in the world
Try us on twitter and be one of the best informed people on earthquakes in the world.

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