Posts Tagged ‘Canary Island’

El Hierro quietens down and effects of undersea eruptions are visible from space

October 14, 2011

From iweather

The Moderate Resolution Imaging Spectroradiometer (MODIS) flying on board NASA’s Aqua satellite captured green stains on the surface of the sea to the south of El Hierro on Friday. (MODIS image here)

MODIS image of El Hierro on the afternoon of Friday 14 October 2011

MODIS image of El Hierro on the afternoon of Friday 14 October 2011: image iweather

In the above image two large green stains are visible on the surface of Las Calmas Sea. In addition to the stains, officials from Spain’s Instituto Geográfico Nacional (IGN) have reported a strong smell of sulphur and dead fish floating on the surface.

The IGN said the large stains emanated from two fissures on the sea bed, approximately 700-1000 metres below the surface.  Scientists say they are hopeful this week’s eruptions will reduce pressure and the potential for eruptive activity occurring on the 285 square kilometre island. …

.. A ROV (Remotely Operated ‘underwater’ Vehicle) is scheduled to arrive in El Hierro on Monday to undertake a seabed study.

The eruptions take place amidst an unprecedented earthquake swarm in El Hierro. The number of earthquakes recorded since July 17, 2011 on El Hierro has now exceeded 10,500.  The number and intensity of earthquakes has reduced signifcantly in the past 48 hours, however.

Aerial Video Of Sea Surface Stains 

 

 

New undersea volcanic eruptions move closer to El Hierro

October 13, 2011

Earthquakes and volcanos in the Canary Islands cause concern because studies have shown that if they struck El Hierro or La Palma — just north of El Hierro – there is a possibility that a large part of El Hierro island would slide into the ocean and trigger a huge tsunami that could travel across the Atlantic hitting the eastern seaboard of the US in six hours.

Earlier posts are here and here.

Recent earthquake swarms on El Hierro - image: Instituto Geográfico Nacional

Underwater Volcanic Eruptions Edge Closer To El Hierro Mainland 

Two new underwater volcanic eruptions have occurred off the south coast of El Hierro, the smallest and southernmost island in the Canary Islands.

Seismologists say two separate fissures have been identified less than 3.7 kilometres and 2.8 kilometres from La Restinga, a town on the southeast of the island. Authorities have detected a sulphur odour in the area while dead fish have also been spotted floating on the surface of Las Calmas Sea.

The fresh eruptions occurred 48 hours after a subsea eruption, Spain’s first since an eruption on La Palma in 1971, occurred approximately 5 kilometres from La Restinga. The town’s 570 residents were subsequently evacuated as a precautionary measure in the event of volcanic activity moving closer to the island.

The eruptions take place amidst an unprecedented earthquake swarm in El Hierro. The number of earthquakes recorded since July 17, 2011 on El Hierro has now exceeded 10,300.

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. …….

…. A Red Alert was issued by local authorities for the town of La Restinga, where local residents were evacuated from on Tuesday evening. Spanish Prime Minister José Luis Rodríguez Zapatero and cabinet colleagues later attended an emergency briefing on the developing situation.

The IGN says all three of its seismic stations on El Hierro in the Canary Islands have registered a volcanic tremor of low frequency in the south of the island at La Restinga, the southern-most village in the Canaries.

Hundreds Remain Evacuated 

Roughly 600 people were evacuated Tuesday on Spain’s El Hierro Island in the Canaries due to the eruption of a nearby underwater volcano. They remained outside their homes on Wednesday as authorities feared an impending eruption. …. In a press release issued on Wednesday, the Canary Islands government said that although no specific changes have been observed since Tuesday evening, precautions remain in effect: “Among the security measures to ensure the safety of the population remains the designation by the Maritime Authority of Santa Cruz de Tenerife maritime exclusion zone which is closed to shipping, fishing, diving, sports or recreation in the area within a radius of four nautical miles from the tip of La Restinga.”

Ferry crossings to the island also remain suspended. People were, however, allowed to return to their homes on Wednesday under the protection of civil safety officials to retrieve medicines, clothing, and other necessities.

Some took to message boards on Tuesday and Wednesday claiming that a landslide in the Canary Islands could cause a mega-tsunami that would devastate the Eastern Seaboard of the United States. ……

 

El Hierro Volcano Update – Red Alert continues and La Restinga evacuated

October 11, 2011

Update 11/10 – 17:17 UTC People in La Restinga have been evacuated to Valverde with buses and private vehicles. They are asked to stay with family if possible or can spend the night in a student home or in tents in Valverde. La Restinga people who were not at home when the Red Alert was called were denied to enter their homes. This happened also to people living in the higher parts of La Restinga! Police threatened people protesting against the fact they could not get belongings from their houses with high fines.  Only the press is admitted to La Restinga!

Earthquakes upto September 30th - El Hierro: image http://earthquake-report.com

Red alert issued for undersea volcanic eruption of the El Hierro island coast (Canary Islands)

October 11, 2011

From iweather:

El Hierro. Google Maps

El Hierro: Google maps via iweather

Spain’s Instituto Geográfico Nacional (IGN) confirmed on Tuesday that an underwater eruption has occurred five kilometres off the southern coastline of El Hierro, the smallest of the Canary Island. The eruption is Spain’s first since the eruption in 1971 of the Teneguía volcano on the island of La Palma (Canary Islands).

The IGN says all three of its seismic stations on El Hierro in the Canary Islands have registered a volcanic tremor of low frequency in the south of the island at La Restinga, the southern-most village in the Canaries.  The estimated 537 residents of the town were summonsed to a local football field on Tuesday afternoon to be briefed on evacuation procedures.

A Red Alert has since been issued by local authorities for the town. A notice posted on the Emergencia El Hierro website on Tuesday evening stated: “Phase pre-eruptive. It involves the initiation of a preventive evacuation. Make yourself available to the authorities.”

Scientists from IGN and CSIC (Consejo Superior de Investigaciones Científicas), meanwhile, have conducted a reconnaissance flight over the sea to the area south of the island, where they have located dead fish floating on the surface five kilometres from the coast. The dead fish were identified in an area where lower seismic magnitude occurred on October 9, at a depth of approximately 2 km.

The present volcanic activity is understood to be occurring at a depth of 600 metres (just under one kilometre) below sea level, in the Las Calmas sea. …..  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.” ….

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. ……

El Hierro pictured from space by the MODIS satellite on Tuesday afternoon, 11 October

El Hierro pictured from space by the MODIS satellite on Tuesday afternoon, 11 October: image via iweather

More details at http://www.irishweatheronline.com/news/earth-science/geology/volcanic-red-alert-issued-as-residents-are-evacuated-from-el-hierro-town/41346.html