Magnitude 7.4 Quake Strikes Guatemala

A Magnitude 7.4 earthquake has just struck off of the coast of Guatemala in another Pacific subduction quake. There were no immediate reports of damage, and the inland appears to have been spared major shaking due to the mountain ranges that seem to have served as a buffer. The quake occurred off of Guatemala's west coast at a depth of 41.6km, which is also why the surface intensity must have felt a bit lower (shallower quakes are typically a lot more damaging).

Google Earth snapshot with USGS real time quake plugin.

There are no immediate detailed reports for this quake. A blog on CNN is the most up-to-date at this time. There was no threat of a tsunami according to the Pacific Tsunami Warning Center, who's statement is below:

"TSUNAMI INFORMATION STATEMENT NUMBER 1
NWS PACIFIC TSUNAMI WARNING CENTER
EWA BEACH HI 643 AM HST WED NOV 07 2012
TO - CIVIL DEFENSE IN THE STATE OF HAWAII SUBJECT - TSUNAMI INFORMATION STATEMENT
THIS STATEMENT IS FOR INFORMATION ONLY.
NO ACTION REQUIRED.

AN EARTHQUAKE HAS OCCURRED WITH THESE PRELIMINARY PARAMETERS ORIGIN TIME - 0636 AM HST 07 NOV 2012 COORDINATES - 14.0 NORTH 92.2 WEST LOCATION - OFF THE COAST OF CHIAPAS MEXICO MAGNITUDE - 7.5 MOMENT EVALUATION

BASED ON ALL AVAILABLE DATA A DESTRUCTIVE PACIFIC-WIDE TSUNAMI IS NOT EXPECTED AND THERE IS NO TSUNAMI THREAT TO HAWAII. REPEAT.

A DESTRUCTIVE PACIFIC-WIDE TSUNAMI IS NOT EXPECTED AND THERE IS NO TSUNAMI THREAT TO HAWAII. THIS WILL BE THE ONLY STATEMENT ISSUED FOR THIS EVENT UNLESS ADDITIONAL DATA ARE RECEIVED. "

There are many volcanoes int he area, as this epicenter lies along the so-called Pacific Ring of Fire. Volcanoes in the area include (from NW to SE):

Tacaná
Tajumulco
Santa Maria (currently erupting)
Almolonga
Santo Tomás
Tolimán
Atitlán
Fuego
Acatenango

Quakes of this magnitude can affect seismicity in active volcanoes, especially ones that frequently erupt, or have a very pressurized magma chamber. It is unclear at this time whether or not this will be the case.

Fuego Volcano in Guatemala Forces Evacuations

The very frequently active stratovolcano in Guatemala, Mt Fuego (Mountain of Fire) has begun eruptions that have forced the evacuation of some 33,000 residents from nearby towns and villages. Last week a powerful explosion took place that produced minor pyroclastic flows and deposited ash on nearby towns, but today's eruption was much more powerful, producing rocketing clouds of gas and ash that forced the immediate evacuation of the surrounding area, and producing ash clouds reaching over two miles into the sky.

The volcano has not erupted with this intensity since at least 1999, a Guatemalan volcanologist stated, who is  familiar with the volcanoes history.

Fuego is one of Guatemala's most active volcanoes, and has been in near constant eruption since record keeping began when the Spanish colonized the area in 1524.

The main dangers of this volcano are from pyroclastic flows, which can reach incredible speeds on land, and even more so over water; lahars, a deadly mixture of water, ash, rock and debris that can inundate and crush entire villages off of maps; and ashfall over cities which can cause major respiratory problems for people, and animals who inhale the fine glassy shards that make up volcanic ash.

Currently, ashfall is falling about 25km from the summit, but that will likely increase if the eruption becomes more intense.

In this scenario, people would be advised to wear breathing masks. If you do not have a breathing mask, breathing through a wet cloth will do just as well, if not better. Eye protection such as swim goggles is also highly advisable, as the fine ash will also irritate the eyes to the point that you cannot see and are in a lot of pain. People should avoid being outdoors if possible, and seek higher ground if it is raining. Rain and ash are a deadly combination.

If you have supplies such as batteries, flashlights, tents, etc, you should be in good shape. No doubt the people in Guatemala are used to living next to this volcano, so I am sure they have gone through these drills before. It will be curious to watch and see if this volcano increased in intensity, or decreases in the coming weeks.