Understanding the M 7.1 Ecuador earthquake

USGS Tectonic Summary for the M 7.1 Ecuador earthquake

This major earthquake occurred within the lithosphere of the Nazca plate. The earthquakes of Ecuador and most of western South America are due to strains generated by ongoing subduction of the Nazca plate beneath the South America plate.
At the latitude of the earthquake, the oceanic Nazca plate moves east relative to the South America plate at a rate of about 7 cm per year. It is overridden by the South America plate at the Peru-Chile trench, west of the Ecuadoran coast, and sinks into the earth’s mantle beneath the South America plate. The subducted Nazca plate is seismically active to depths of about 650 km.
This earthquake occurred as normal faulting within a segment of the subducted plate that has produced frequent earthquakes with focal depths of 160 km to 200 km beneath the earth’s surface. A magnitude 6.7 earthquake in 1971 was situated 60 km to the southwest of the August 12, 2010, earthquake at a depth of 170 km.

Earthquakes that have focal-depths between 70 and 300 km are commonly termed “intermediate-depth” earthquakes, as distinguished from “shallow-focus” earthquakes, having depths less than 70 km, and “deep-focus” earthquakes, having depths greater than 300 km. Intermediate-depth and deep-focus earthquakes represent deformation within subducted plates, rather than deformation at plate boundaries.
Intermediate-depth and deep-focus earthquakes typically cause less damage on the ground surface above their foci than is the case with similar magnitude shallow-focus earthquakes, but large intermediate-depth and deep-focus earthquakes may be felt at great distances from their epicenters.

The above explanation can be seen very well on the map at right. More to the east means a deeper and deeper subducted Nazca plate.  Yellow line are the plate boundaries. The blue earthquake dots are the kind of earthquakes as today in Ecuador.

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Massive (deep) earthquake of M 7.2 hits Ecuador

Last update in green below

Earthquake Report comment :
As the earthquake is very powerful, but very deep it will be felt far away from the epicenter
All data is preliminary at this point as data has to be recalculated by seismologists.
At first sight the epicenter lies in a wilderness area down from the Andes to the east.
First messages from Quito signal a light shaking.
Earthquake downgraded to M 6.9
Closest city to the epicenter : Puyo
GDACS has just issued a GREEN earthquake alert, thus minimizing the impact.
Only 6,257 people live in an area of 50 km around the epicenter.
As the earthquake occurred overland NO tsunami treat exists.

Ambato was completely destroyed by a large earthquake on the afternoon of 5 August 1949. Tragically, the entire city and surrounding villages were reduced to rubble; in total 50 towns and villages were destroyed. Six thousand people died, and thousands more were left homeless and destitute by the disaster.
Among the dead were a group of children preparing to receive their first communion  in the main church, and in the central Montalvo Park, the trees and flowers had disappeared into a rift in the earth. So many dead were found that there was not enough room in the city’s central cemetery for them all; these people were buried in remains of the park.
The entire city was rebuilt from the ground up and earthquake-proofing the city became a main concern of the inhabitants. (Source : Wikipedia)

Update 14:34 UTC : The Ecuadorian on-line newspapers mention none to limited articles at the earthquake. It was felt down to Guyaquil, but very light. Based on our experience, people start sending emotional articles to the newspapers, but so far nobody did. Of course, we will have to wait for news of the epicenter area, but due to the depth of the quake ER does not expect much damage.  USGS calculation models give only a moderate shaking  in the earthquake epicenter area.  Probably this earthquake will be a frightening experience, but with a good end. Aftershocks (mostly in de same hypocenter depth will be probable for the coming hours and days).
The earthquake lasted for approx. 1 minute and was located in between the Provinces of NAPO and PASTAZA, well know by tourists.

Update 16:06 UTC : One of the bigger towns near the epicenter was Ambato, totally destroyed during another earthquake in 1949, outside of some small cracks and a small landslide blocking traffic for some time, no other damage was reported.  In Ambato, as well as in Riobamba and in Latacunga people ran immediately on the streets. They told reporters that the shaking went on for more than 40 seconds.
Even as far as Guyaquil, alarms started to ring, walls where shuddering and some older houses got cracks.
in Santo Domingo de los Tsáchilas power went down all over the city, but no damage was announced.

Find hereunder links to 3 articles of El Commercio (leading newspaper in Quito/Ecuador). Articles are in Spanish
Sismo de 7,1 grados se sintió hoy en Ecuador
La Amazonía peruana también sintió el sismo producido en Ecuador
El sismo de 7,1 alarmó a varios sectores del país

Read also the : Understanding the M 7.1 Ecuador earthquake

Most important Earthquake Data:
Thursday, August 12, 2010 at 06:54:14 AM at epicenter
Depth (Hypocenter) : 211 km
Geo-location(s) :
145 km (90 miles) E of Ambato, Ecuador
155 km (95 miles) ENE of Riobamba, Ecuador
155 km (95 miles) SSW of Nueva Loja, Ecuador
175 km (110 miles) SE (136°) from QUITO, Ecuador

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 historic earthquakes map
GDACS Green Earthquake Alert (Global Disaster Alert and Coordination System)
Ecuadorian Institute of Geofysics

* 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.

Experience the Magnitude 7.3 Vanuatu earthquake

The New Zealand Herald has published  a live footage video of Tuesday’s earthquake in Vanuatu as it happened.

Luckily this house was earthquake-proof build. In the video you will see the extreme importance of fixing cubbards, closets, etc. to the wall.

Read also an article in the same New Zealand Herald of  the earthquake experience of Ben McKenzie, who has been working for the New Zealand High Commission in Vanuatu.  It gives a very good impression of what people live through.

“For a good 10 seconds, you almost couldn’t walk – it was throwing you around that much and people in the supermarket had to be evacuated because of all of the damage that was being done,” he told Ten Network in Australia.

Earthquakes list August 12, 2010

Useful information to read this daily earthquake list
This earthquake list covers minor and major earthquakes  in the world.
If a more detailed page is present, the earthquake line will be linked to the detailed page.
For your comfort, we will provide in most cases Google Satellite Map links to give you an idea where the earthquake struck, which terrain it happened and if villages or cities are located in the immediate vicinity.
The page is regularly updated to add new quakes.
Minor earthquakes are earthquakes without or with little damage risk.  In most cases these earthquakes have a Magnitude smaller than M 5.0 OR earthquakes with an hypocenter (depth) of more than 100 km OR earthquakes up to M 5.9 with an epicenter far away from populated areas.
The reference for the time zone is UTC (Coordinated Universal Time)

M 4.0  2010-08-12   15:51  Depth 1 km   KAZAKHSTAN-XINJIANG BORDER REG.
Same area and also here …  spectacular glaciers

M 4.3  2010-08-12   15:23  Depth 80 km  KAZAKHSTAN-XINJIANG BORDER REG.
Epicenter in the middle of an incredible glacier landscape.  To deep to be felt well, unless you where walking on the glacier !

M 5.2      2010/08/12 12:53  Depth 35 km      VANUATU
Aftershock of the M 7.3 Vanuatu earthquake from August 10

M 6.9      2010/08/12 11:54  Depth 190 km      ECUADOR
Click on the link for extensive coverage

M 4.7      2010/08/12 09:46  Depth 15 km      GREECE
Shallow light quake with epicenter 30 km of Ioannina (pop. 64,000) and 6 km from Paramithia (pop 2,568)

M 5.3      2010/08/12 08:56  Depth 35 km      VANUATU
Again an aftershock of the M 7.3 Vanuatu earthquake from August 10

M 4.8      2010/08/12 04:48:35  Depth 637 km FIJI REGION
Very  deep hypocenter = no impact on the neighboring islands

M 4.9      2010/08/12 02:56:02 Depth 35 km     VANUATU (aftershock)
This is an aftershock of the M 7.3 Vanuatu earthquake from August 10

M 4.3      2010/08/12 02:23:05 Depth 4 km     WESTERN TURKEY
Light earthquake in an unpopulated area

M 5.0      2010/08/12 01:24:19 Depth 43 km     CENTRAL PERU
No villages in a wide area around the epicenter

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 August 12, 1953 – Kefalonia, Greece

“In memory of” will highlight 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.

M 7.02   12-08-53  Depth 15 km   Greece –  killing 800 people

The earthquake of 1953 on Kefalonia was One of the greatest disasters ever.
On August 12, 1953 at 09:24 UTC, the most destructive of the four earthquakes hit the island. The earthquakes destroyed almost every house and killed approx. 800 people. The worst earthquake had a Magnitude of 7.2.
The epicenter was on the southern tip of the island and raised it by 60 cm! The watermarks on rocks around the coast bear testimony to this fact. The only areas that escaped destruction were on the northern side.
The island of Kefalonia is just east of a major tectonic fault. This is where the European and the Aegean plates meet at a slip boundary.
The worst blow to the economy was that 100,000 residents left the island to live elsewhere.

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