7.6 Quake Oaxaca, Mexico

Major 7.6 earthquake on Mexico Pacific coast: USGS

MEXICO CITY | Tue Mar 20, 2012 2:37pm EDT

(Reuters) - A major 7.6 magnitude earthquake struck 120 miles east of Acapulco on Mexico's Pacific coast, the U.S. Geological Survey said on Tuesday.

The USGS located the epicenter of the quake at 15 miles east of Ometepec in Guerrero state at a depth of 10.9 miles.

The Pacific Tsunami Warning Center said the inland earthquake would not generate a destructive widespread tsunami, but there was the possibility of some local tsunami effects.

The quake was felt in Mexico City where buildings shook and office employees fled into the street, according to a Reuters witnesses. Cell phone lines were down and traffic snarled in the capital moments after the quake.

No damage was reported in Oaxaca, near where the quake hit, according to local television.

Earlier it had been reported at 7.9 magnitude and initially as 7.6 magnitude.

It was felt hard as hell in Mexico City.
Citizen civil protection worked real fine, again. No casualties.
Home and cell phones went out, so did electricity.
About half hour later, you could send SMS.
Electricity is back, as you can see.

Mexico dodged a bullet with this one.

Good to hear that you have power again, fbaezer, and that there have been no casualties thus far.

Looks like there was quite a bit of destruction after all. There may end up being some casualties when the collapsed homes are searched.

http://www.cnn.com/2012/03/20/world/americas/mexico-earthquake/index.html

Mexico City (CNN) -- Hundreds of houses collapsed after a strong earthquake that rattled residents in southern Mexican resort towns and the nation's capital Tuesday, officials said.

The quake had a magnitude of 7.4, according to the U.S. Geological Survey.

Its epicenter was about 15 miles (25 kilometers) east of Ometepec, Guerrero, the USGS said, and its depth was about 12.4 miles (20 km).

In the nearby town of Igualapa, officials reported that at least 800 houses had collapsed, the Guerrero state government said in a statement. There were no immediate reports of serious injuries or deaths.

More than an hour after the quake, residents in Ometepec were feeling aftershocks, said Francisca Villalva Davila, the city's comptroller.

"There are many cracked ceilings, many houses that collapsed," she told CNN en Español.

About five out of every 10 houses in the municipality, where about 50,000 people live, saw significant damage, the comptroller said.

"Tiles are falling. We are feeling constant aftershocks. It's shaking right now," she said.

The USGS initially reported the magnitude of the quake at 7.9, but later revised that figure downward. Mexican President Felipe Calderon said in a Twitter post it was 7.8.

Residents rushed into the streets after feeling the temblor in Mexico City, about 200 miles (320 km) away from the epicenter. Tourists and residents also felt the earthquake in the resort city of Acapulco.

Calderon said that there were no immediate reports of serious damage, and that the nation's health system was operating normally.

"There are some broken windows, much fear, much panic," he said.

Residents in the southwestern states of Oaxaca and Guerrero and the eastern state of Veracruz reported that phone service had been knocked out.

Multiple houses collapsed in the Ometepec area, but officials have no reports of deaths or injuries, Guerrero state Gov. Angel Aguirre told CNN affiliate Televisa.

Government helicopters were surveying the area, he said, and officials were preparing shelters for displaced residents, he said.

Authorities in Mexico City were surveying buildings, schools and hospitals to evaluate damage, Mayor Marcelo Ebrard said.

A pedestrian bridge fell on a minibus during the quake, he said, but there were no injuries.

Some buildings had cracks and broken windows, he said in a Twitter post.

Earthquakes are a frightening experience for the more than 20 million residents of Mexico City, where about 10,000 people perished in the area after a massive quake in 1985.

The city, built on volcanic ash and clay, is particularly vulnerable to temblors.

I first heard it was in Guerrero and it looks centered there by the map. Oops, checked again - the center looks smack on the border between the two states..

On Mexico City, I read that a lot of people ran out of buildings along the Reforma in panic, I figure a lot with memories of 1985.

Fear and bitter memories, yes.
Panic, no.

I hear there are lots of after shocks?

How do you tell an after shock from another bloody earthquake?

I'd be panicking....and I've only experienced tiny tremors.

I am wishing all of you guys the best. Sometimes nature sucks.

I haven't felt a single aftershock.
In one of the bigger ones, someone at the office said "it's trembling". One or two seconds passed, it didn't get worse. Then someone else said: "Replica". And everybody resumed working.
When you live in an earthquake zone (Western, Central and Southern Mexico, California, Chile, Japan, Italy, Iran, parts of China) you get to identify, from an early age, a tiny shake or an aftershock from a big one (or a big aftershock, as in 1985).

It's now official. No deaths because of yesterday's earthquake.
200 homes destroyed in the Amusgo indian zone of Guerrero
2000 homes destroyed in diverse zones of Oaxaca
200 schools closed for verification
2 buildings vacated in Mexico City
600 buildings in MC being revised
one vehicle bridge has to be rebuilt because of a fault that almost broke it
One subway line was closed for 23 hours because the quake turned parts of the rails into waves. They were fastly substituted.

I just want to remember that this was a 7.9 earthquake.
Haiti's (300 ooo dead) was a 7.0
Tangshan China 1976 (240 000 dead) was a 7.5
California: The Great San Francisco Earthquake (3000 dead) was a 7.4, the World Series earthquake in 1989 was a 6.9 (63 dead) and the Northridge quake, a 6.7 (60 dead)

2,000 homes!!!

Given the magnitude, i am so glad that nobody was killed.

Not one death!

That's both great news and extremely impressive.

Is architecture the main reason? Codes? Or something else?

dlowan, the personal experience of feeling an earthquake varies from person to person (some are more sensible than others, I consider myself middle-of-the-way) and the place you're in is more important than the force of the quake.
Tuesday's quake was the third strongest in the Fbaezer scale.

Number one was on October 24th, 1981. A measly 7.3 on the Richter scale. But I was living in an apartment built over what used to be canals on the Prehispanic era, my oldest son was only a few months old and the walls turned from square to left-sided trapeze back to square and then to a right-sided trapeze. I was scared shitless.

Number two was the Big One, September 19, 1985, the very deadly 8.3 that changed our lives. I was living in an apartment built over what used to be normal farming land, and the building had an anti-seismic hidraulic system. I was holding my second son, a baby, in my arms at the gate of the apartment and the older one asked: "Is this an earthquake, dad?". I answered: "Nah, it's just a tremor", only to correct myself a few moments later: "Yes, it's an earthquake, and a big one".
Later on, we learned that standing below a door or table is wrong if the earthquake is big. It may prevent you from dying because of a falling ceiling, but not from being trapped and die of asphyxia.

Number three was last Tuesday. I was at home, a house built over what used to be a swamp near the central lake in Prehispanic times. All the houses made a distinctive "crack" sound. I went out to the backyard. So did the cleaning lady who became very worried about her young child left with a relative.

Number four was the aftershock of the Big One, September 20, 1985. That was a 7.6. I recall writing about it in another thread titled "Our Earthquake".

This is, officially the strongest earthquake my 18 year old daughter has felt. She felt it only a little bit stronger than a 6.7 last December. Why? On Tuesday she was at her school's library, in a part of the city built over dried lava, where quakes are felt the least and do the least damage; on December she was alone at our house, while her mother and I had gone to a rock concert.

I would think timing was a big issue. It looks like it happened around noon. If it had happened earlier or later the outcome would probably have been much worse. Thank god for small miracles.

There have been improvements in architectural protocols in Mexico City after the 1985 disaster. According to experts, and given the damp soil characteristics of the city, vibration affects most a building in Mexico City if it's between 7 and 10 stories high. Some buildings were cut, others were made taller and most new buildings have anti-seismic hidraulic systems. Still, there are many 7-10 story buildings built before 1985.
Drills and codes are also important. At least twice a year earthquake drills are made in Mexico City (one is on September 19th, day of the deadly one) and in most towns in Central and Southern Mexico.
In 1999 there was a 7.0 earthquake in Puebla. In a grade school, all the children worked through what they had learned in the drill and assembled in the ample central patio... to see their school crumble around them. Not one of them died.
There is also an alarm system. Since most of the tough quakes originate in the Pacific. As soon as the quake is felt, an alarm sounds in big office buildings. Since the quake takes from 30 seconds to one minute to arrive to Mexico City, it gives people time to start fleeing the buildings. Unluckily this cannot work on towns and cities near the coast.

Good, I believe you instead of whatever newspaper thing I read.

I don't know what time could be worse. Noon is work and school time here. We have "lunch" at 2:00 or 3:00 (actually it's the big meal of the day).

Thanks for the thorough answer, exactly what I was curious about.

A new replica 5.4 Richter scale at 10:46 am.
Didn't notice it.
Someone in twitter wrote: "No self-respecting Mexico City dweller widens his/her eyes with a less-than- 6.0 earthquake".
By the way, Tuesday's shake was downgraded to a 7.4.

Quite often quakes seem to hit when people are sleeping. Actually, it seems most disasters tend to happen during sleeping hours. That seems to up the ante for quakes in the past. At noon, most people are out of their homes and generally when quakes hit, it's often homes that receive the worst damage. And if what I'm reading is correct, it was mostly people's homes in the south that were affected.
I'm not saying Mexico wasn't prepared. I'm very happy no one lost their lives.