Volcano in Canary Islands May Be Getting Ready for Eruption

The Hierro -- or El Hierro -- volcano located in the Canary Islands may be getting ready for eruption, according to information on the website Earthquake-report.com. An earthquake swarm that has numbered 700 or more small quakes under the volcano has occurred recently, raising concern that the volcano may be working up to an eruption.

What is an earthquake swarm? It is a series of small magnitude earthquakes that strike in the same location over a (usually) short time period. Earthquake swarms are common precursors and warnings to volcanic activity.

The Canary Islands are located off the northwestern coast of Africa, near the border between Morocco and Western Sahara. They are a chain of islands known as an archipelago and are legally a nationality of Spain. There are 13 islands in the archipelago and the Canaries are a popular tourist destination.

The third-largest volcano in the world is located in the Canary Islands -- Mount Teide on the island Tenerife. Teide is third in height from the base after Hawaii's Mauna Loa and Mauna Kea.

El Hierro is the name of one of the islands in the Canary chain and the volcano is relatively young. According to Volcano Live, the "hotspot" that is responsible for volcanic activity in the Canary Islands is currently underneath El Hierro Island.

Volcano Live explained there are actually three volcanic structures on El Hierro Island -- an "elongated topographic ridge (the Southern Ridge) and two semi-circular volcanic cones (Tinor volcano, El Golfo volcano). " Hierro is actually a shield volcano -- a volcano that is characterized by eruptions from vents that are cracks or fissures in the surface of the volcano.

Typically, shield volcanoes do not have the classic steep-sided cone-like volcano appearance that is found in stratovolcanoes. Shield volcanoes have lava flows that build wide mountains with very shallow slopes. Other examples of shield volcanoes are the volcanoes that make up the Hawaiian Islands, and obviously, the Canary Islands.

It is uncertain when El Hierro last erupted, but it is believed there may have been an eruption in 1793. The location of the current earthquake swarm is at the northwest part of the island near the El Golfo cone, which, according to Volcano Live, was the site of a landslide that was responsible for a tsunami 50,000 years ago that measured just over 300 feet in height. The recent earthquakes have measured between 1 and 3 in magnitude and were at depths that measured three to nine miles.

Tammy Lee Morris is certified as a Community Emergency Response Team (CERT) member and is a trained Skywarn Stormspotter through the National Weather Service. She has received interpretive training regarding the New Madrid Seismic Zone through EarthScope -- a program of the National Science Foundation. She researches and writes about earthquakes, volcanoes, tornadoes, weather and other natural phenomena.