Subsea Volcanic Eruption Underway Near El Hierro (The Canary Islands)
By Mark Dunphy - Mon Oct 10, 4:18 pm
El Hierro, The Canary Islands, from space in this MODIS satellite image on Oct. 7 2011
A submarine volcanic eruption is taking place approximately 5 kilometres off the southern coast of El Hierro, the smallest of The Canary Islands.
The Mayor of La Frontera (El Hierro), David Cabrera, confirmed in an interview on Radio iron Garoé that ‘underwater eruption’ is taking place about 900 metres beneath the sea surface five kilometres south of La Restinga. The eruption has been ongoing for four hours, the Mayor said.
Spanish newspaper laopionion.es quoted the Minister of emergencies of the Cabildo of El Hierro, Maria of Carmen Morales, as saying the eruption is taking place because ‘the seismic movement of 4.3 occurred on Saturday afternoon caused a fissure, from where the energy is been released’. Scientists remain unclear if the emissions are gas or lava.
A meeting of PEVOLCA – Actualidad Volcánica de Canarias, comprising representatives of Instituto Geografico Nacional (IGN) and The Canary Islands Government, took place on the Spanish Island. In a statement issued shortly before 4 p.m. local time, the IGN stated (translated from spanish language press release): “…although there is no certainty that at the moment is producing an underwater volcanic eruption, since the last morning there has been a release of fluids and volcanic gas on the southern coast of the island.”
“Scientists from IGN have reported to the direction of the Plan all the indicators that have been analyzed to point towards the possibility of the beginning of an eruptive process that has changed the type of waves that have registered seismographs in the last hours, implying the beginning of emission of gases or lava…”
“The helicopter of the emergency and rescue of the Government of the Canary Islands (GES) group has done reconnaissance flights during the morning without exit of volcanic material to the surface.”
“Although this activity is not exposed to, the direction of the PEVOLCA encourages people to perform their usual tasks normally and to remain attentive to any unusual activity”, the statement added.
Meanwhile, La Agencia Estatal (CSIC) scientists equipped with special detection cameras have been making numerous sorties over coastal areas of El Hierro in an attempt to verify the existence and scale of the underwater eruption. This is Spain’s first volcanic eruption since 1971 when the erupted of the Teneguía volcano on the island of La Palma (Canary Islands), located to the north of El Hierro.
Initial reports of the eruption were received from crews on board four separate ships. On Monday afternoon, Terra Noticias/Agencia EFE reported that an eruption occurred 2000 metres below sea level in the Las Calmas sea at 10.43 local time (05:43 EDT). Spanish newspaper El Mundo placed the depth of the eruption at 13oo metres.
Local media agency Canarias7 reported on Monday that Government authorities have suspended ferry activities to and from the 285 square-kilometre island. English language newspaper islandconnections.eu reported: “The martime chief for the province of Santa Cruz de Tenerife Antonio Padrón has issued a recomendation that boats should not sail closer than four miles off El Hierro. Divers have also been told to suspend all activities.”
Background To The Eruption
The eruption takes place amidst an unprecedented earthquake swarm in El Hierro. The number of earthquakes recorded since July 17, 2011 on El Hierro has now exceeded 10,000.
Hierro, a shield volcano, has had a single historic eruption from the Volcan de Lomo Negro vent in 1793. The eruption lasted approximately one month and produced lava flows.
The recent surge in the number and intensity of earthquakes prompted officials from the IGN and The Canary Islands Government to raise the alert level for the Hierro volcano to ‘Yellow’ late last month. The alert remained in place on Monday, but the estimated 11,000 residents of El Hierro were being reassured not to be alarmed.
The majority of the earthquake activity shifted from El Golfo in the island’s northwest to beneath the Las Calmas Sea in the south earlier this month. Surface deformations exceeding 35mm have also been recorded on the island in recent weeks.
Evacuations
A dramatic rise in recorded earthquakes on El Hierro prompted officials to evacuate some local residents, shut El Hierro’s main tunnel, and close local schools on 27 September.
The Spanish Civil Guard (Guardia Civil) advised almost 50 residents of the municipality of La Frontera to leave their homes because of landslide fears. Two units of the Spanish military’s emergency intervention unit (EMU) were also placed on standby to depart the nearby island of Tenerife to assist in the possible evacuation of hundreds of other El Hierro residents.
Meanwhile, the island’s main tunnel (Tunel del Golfo), which links Frontera to Valverde, was shut forcing motorists to travel across the 280-sq-km island via a mountain road. The Cabildo de El Hierro also ordered the closure of schools.
Latest seismic activity on El Hierro
IGN graphic of recent earthquakes (marked in red) on El Hierro
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