Volcanoes

In El Salvador there are 22 volcanoes. They are part of the circum-pacific ring of fire and they are related to the subduction of the ocean Coco's Plate under the Caribbean tectonic plate. One of those is Chaparrastique Volcano and it's considered one of the most active with 26 eruptions in the past 500 years. 

Apaneca is part of E-W stratovolcanoes in western El Salvador. Cerro Singuil is a large scoria cone SE of Volcan Chingo in the interior valley of El Salvador. This volcano has a well preserved summit crater and it belongs to a young volcanic field of cinder cones and explosion craters. Izalco was born in 1770 and is the youngest. Fumarolic activity increased in 1999. Santa Ana is a stratovolcano of San Salvador city. It is the highest volcano and one of the most active. Coatepeque is a 7x10 km wide caldera. A caldera is formed by the collapse of several overlapping stratovolcanoes E of Santa Ana volcano. San Diego is a young volcano located at the border between El Salvador and Guatemala. San Salvador is a massive stratovolcano NW if El Salvador City. A small seismic swarn occurred August 1999 and the last eruption was in 1917. Cinotepeque is a group of 4 young cinder cones on both sides of Rio Lempa. Guazapa is an eroded basaltic stratovolcano.  Ilopango is a 8x11 km wide caldera. The last eruption was 1879-1880 and it constructed a new lava dome which emerged above the caldera. San Vicente is a twin-peaked stratovolcano SE of Lake Iloopango. It's the second highest volcano. In 2009 Hurricande Ida caused large mudflows from the flanks of San Vicente. Apastepeque is a young volcano fiels 8 km N of San Vicente. It contains 24 closely cinder cones, lava flows, lava domes, and lava maars. Taburete is a basaltic stratovolcano located SW end of a cluster of volcanoes between San Vicente and San Miguel volcanoes. Tacapa is a complex basaltic stratovolcano located NW end of a cluster of stratovolcanoes between San Vicente and San Miguel volcanoes. Usulutan is a stratovolcano at the SE end of the cluster of volcanoes between San Miguel and San Vicente. Chinameca is a small stratovolcano next to San Miguel volcano. San Miguel is a symmetrical stratovolcano and one of the most active volcanoes of the country. There was small eruptions in 1995, and 1997. A large eruption 2000-2001, gas and steam emisions with some ash in 2002, and 2002-2006 it was restless with periods of increased seismic activities. Laguna Aramuaca is a lake filled explosion crater 10 km SE of San Miguel and might have formed less than 10,000 years.  Conchagua is an eroded stratovolcano on the western side of the Gulf of Fonseca. Conchaguita is at the SE tip of El Salvador. It is a sharp-topped cone with a 100 m wide summit crater at the southern end.

El Salvador's Emergency Plan of  Action is to immediately evacuate the surrounding cities. The Red Cross assists, and provides shelter during the response phase. Families are trained in health care, hygiene, and sanitation because of the effects of  the volcanic eruption. Red Cross responds immediately by deploying volunteers to the affected area to assist with the evacuation to collective centers and provide pre hospital care with support of ambulances. If needed immediate assistance is asked of other countries. 

I found this clip on Youtube, enjoy!

https://www.youtube.com/watch?v=X62jC0kmRLs

• http://reliefweb.int/report/el-salvador/el-salvador-volcanic-eruption-emergency-plan-action-epoa-dref-operation-mdrsv00-1
• http://www.volcanodiscovery.com/el-salvador.html
• http://gocentralamerica.about.com/od/elsalvadorguide/p/El-Salvador-Volcanoes.htm

Tsunamis
Tsunami's are just larger versions of regular waves, they have a trough and a crest. They consist not of moving water but movement of energy through water. The energy in normal waves comes from the wind, tsunamis are caused by energy originated underwater from a volcanic eruption, a submarine landslide, or an earthquake on the ocean floor. Tsunamis can move hundreds of miles per hour, and builds in height once they reaches shore.

El Salvador is an environment of high stress and and large earthquakes which makes the coast vulnerable to tsunamis.  Between 1859 and 2002, 11 major events have struck El Slavador. Two of these events caused massive destruction and deaths. Five were triggered locally, three regionally, and three by distant earthquakes in the Chilean, Columbian, and Aleutian subduction zones. In El Salvador, earthquakes of magnitudes of 7 or higher, having epicenters offshore, or onshore could trigger tsunamis. Tsunami hazards indicate that the entire Pacific Coast of Central America is at risk for tsunamis. Particularly there are nine communitiesexposed to the risk of tsunamis and they are: La Union, San Rafael de Tasjera, El Zapote, Marcelino, La Libertad, El Majahual, and Acajulta, Barra de Santiago and Garita Palmera.

• https://www.youtube.com/watch?v=Wx9vPv-T51I
• http://specialpapers.gsapubs.org/content/375/435.abstract
• https://books.google.com/books?id=j52TYoUOUjMC&pg=PA266&lpg=PA266&dq=tsunami+el+salvador+hazard&source=bl&ots=OQiK5ytk6P&sig=oik7XtMX62AnRc3b_gN9SxoW-_Q&hl=en&sa=X&ved=0CEMQ6AEwCmoVChMIn5GIusH9xwIVApqICh2hgwFj#v=onepage&q=tsunami%20el%20salvador%20hazard&f=false
• http://www.nat-hazards-earth-syst-sci.net/13/2927/2013/nhess-13-2927-2013.pdf

Earthquakes
In the last hundred years, El Salvador has had 13 major earthquakes. In 2001, one of the greatest earthquakes that has hit El Salvador happened. The Richter scale measured it at a 7.6 magnitude. The earthquake struck with the epicenter at 60 miles and it happened southwest of San Miguel. A month after another earthquake hit El Salvador. Together, these two earthquakes did major damage. Killing 944, injuring 5,565, and a total of 1,364,160 victims. This earthquake was one of the most powerful earthquakes to hit Central America in 20 years. The earthquakes occurred within the Cocos-Caribbean subduction zone. El Salvador is located at the western part of the Caribbean Plate, where it is subducting the Cocos plate. Subduction zones like this one are very complex and produce many earthquakes from multiple sources. Intraplate earthquakes occur within the crust of the overriding Caribbean plate. Deeper intraplate earthquakes occur within the subducting Cocos plate. The earthquake sequence in the El Salvador has involved intraplate faulting in both the Cocos and Caribbean plates.

The Pacific Disaster Center has chosen El Salvador to participate in a National Disaster Preparedness  Assessment because of it's diverse hazard profile. El Salvador is at risk for volcanic activity, earthquakes, flooding, and landslides. El Salvador also has strong disaster management culture, with active civil military preparedness and response engagements. 

Reference Centre for Institutional Disaster Preparedness established at the Salvadorean Red Cross Society in 2005, with the support of the International Federation of Red Cross and Red Crescent Societies. It was created to strengthen disaster preparedness and vulnerability reduction programs for the seven Central American National Societies.

http://news.bbc.co.uk/onthisday/hi/dates/stories/january/13/newsid_2554000/2554149.stm

http://earthquake.usgs.gov/earthquakes/eqarchives/year/2001/2001_01_13_seis.php

http://geogon.wikispaces.com/Earthquakes

http://www.pdc.org/UserFiles/File/NDPBA_ElSalvador.pdf

http://www.ifrc.org/en/news-and-media/news-stories/americas/el-salvador/reference-centre-for-institutional-disaster-preparedness-in-el-salvador-58240/

Plate Boundaries 

El Salvador is one of the most active, earthquake vulnerable areas in the Western Hemisphere. The country is in between two active tectonic plate movements. On the southern part of El Salvador, Coco's plates pushes under the Caribbean Plate, which causes frequent earthquakes near the coast. As the ocean floor is forced down, the rocks melt, and that causes volcanoes and geysers. On the northern side of El Salvador, the North American Tectonic Plate pushes one edge of the Caribbean Plate, creating a major fault. This fault causes earthquakes in the northern part of El Salvador. There are three seismic source, intra-slab earthquakes within Coco's plate, crustal earthquakes within the upper plates, and interplate earthquakes along the boundary. 10 of the 16 earthquakes damaging to San Salvador are associated with the volcanic belt, and the other 6 to Coco's plate. El Salvador has more "Ring of Fire" volcanoes than any other central american country. 

• Lifeline Performance of El Salvador Earthquakes of January 13 and February 13, 2001 (Google Books)

• "IGCSE Plate Tectonics and GCSE Plate Tectonics."Greenfieldgeography.03Sept2015
• "El Salvador."Nationalencyclopedia.03sept2015