[Geology2] Cone off El Hierro Island has reached a height of 300 feet

Residents of the village of La Restinga on the island of El Hierro were allowed on Saturday to return to their homes,as the risk of a volcanic eruption subsides. Although the stain in the sea caused by sulphur emitted by the underwater volcano off the coast of the most westerly of the Spanish controlled Canary Islands now surrounds much area of the island, indicators point to the eruption losing strength. As a result the residents of La Restinga, the village closest to the site of the eruption began to return to their homes on Friday night. They had previously been allowed to make only a brief return to their houses in order to collect essential possessions. The permission to allow the residents to return to their village, which has an economy based on tourism and fishing, comes in the wake of explanations by Spanish scientists on Thursday. Carmen Lopez, of the Spanish National Geographic Institute and Joan Marti of the Board of Scientific Investigation said that the eruption was less powerful than first predicted. Early predictions had spoken of a four stage eruption resulting in magma expelled to the surface creating a new island. That now looks a remote possibility after Lopez said indicators such as the strength and depth of earth tremors have been falling and there has been an overall decrease in seismic activity. Marti was more cautious and said that although it could be that an eruption with various phases could still happen, there was no evidence to show that it was the case in El Hierro. He said event will eventually turn out to be an underwater eruption like many others in the region, which is situated close to a fault line in the Atlantic Ocean. Scientists will now continue to monitor the situation until readings return to the normal levels seen until July when seismic activity was first detected.

Spanish scientists say they've mapped the formation of an underwater volcano that emerged in the waters off the Canary Islands earlier this month. The volcanic cone off El Hierro Island has reached a height of 300 feet with a lava tongue still flowing down its side, even though its activity has slowed in the past few days, a release from the Spanish Foundation for Science and Technology said Friday. "This is probably the first time that such a young underwater volcano has been mapped in such high resolution," Juan Acosta of the Spanish Institute of Oceanography said. Within 15 days of the first signs of eruption on Oct. 9, scientists on the institute's research ship Ramon Margalef completed mapping the seabed and the growing volcano with unprecedented precision, he said. "It is spectacular to see how what was once an underwater valley is now a volcanic cone with its descending lava tongue," Acosta said. The base of the volcano lies at a depth of almost 1,000 feet. It is conical, 300 feet high with a base diameter of 2,200 feet and a crater width of 400 feet, the researchers said.

The Spanish research vessel Ramon Margalef has surveyed the vent area of the new ongoing submarine eruption south of El Hierro with the help of a diving robot, and presented a digital model for the news crater, which formed above an undersea valley at 250 m depth and forms a cone rising now more than 100 m containing a 120 m wide crater. Even submarine (pillow) lava flows are recognized on the elevation model presented. If the pictures presented by IEO really are showing the new volcano, it is the first time that the birth of a seamount has been documented this way. In the meanwhile, the eruption continues and produces a large stain of discolored muddy water drifting around the southern and western coast of El Hierro.

Victor Healey