November 8, 2011 – EL HIERRO –
The submarine volcanic eruption that began in mid-October in the Canary Islands continued in early November 2011. The volcanic island of El Hierro sits on a tectonic hot spot in the Atlantic Ocean off of North Africa and Spain. The Advanced Land Imager (ALI) on NASA’s Earth Observing-1 (EO-1) satellite acquired this natural-color image of El Hierro and a plume of volcanic material in the surrounding waters on November 2, 2011. The waters south of the island have been bubbling and fizzing with heat, sediment, bits of volcanic rock, and minerals for weeks, with the plume stretching tens of kilometers. The eruption is believed to be venting about 50 to 100 meters below the water surface, and it is warming the waters by as much as 10 degrees Celsius, according to geologist and blogger Erik Klimetti.
The temperature of erupting basalt can be as hot as 1100 to 1200 degrees C, he notes. “Flank eruptions are one way that volcanoes build up and out of the seafloor—and sometimes above the water surface,” notes marine geologist Dan Fornari of the Woods Hole Oceanographic Institution. “If the magmatism is maintained, platforms can develop between the islands, a la Galapagos. This is also an example of how the ocean acquires its chemical makeup. It’s not just run off from the continents, but also injection and chemical exchange caused by submarine volcanoes.” From October 26 to November 1, the Instituto Geográfico Nacional reported, 540 seismic events (quakes and tremors) were recorded by sensors on the island. Most of the activity was north of the island, at depths of 16 to 23 kilometers, and on the opposite side from where the plume of volcanic material was discoloring the water. More than 10,000 seismic events have been recorded near El Hierro since July 17. -NASA
In the Atlantic Ocean, off the Canary Island
of El Hierro, 20-meter high jets of water are being spat into the air as the sea
boils amid the stench of sulfur. The undersea volcano, which is set to create
new land, is growing ever-nearer to the surface — but is the existing island at
risk from the explosive eruptions? “The monster rises out of the water,”
screamed the Spanish newspaper La Provincia. Scientists, meanwhile, are
being a bit more level-headed about the undersea volcano south of El Hierro in
the Canary Islands; they now believe it is in the third phase of its eruption —
fountains of water have been shooting out of the Atlantic up to 20 meters in the
air over the last few days. On Tuesday, some local residents even saw stones
being catapulted out of the sea.
A seething maelstrom, dozens of meters across,
is bubbling away in the ocean.
Measurements show that the vortices are
significantly warmer than the surrounding water. So far, the volcano has only
shown its explosive power beneath the water. But now the outbursts to the south
of El Hierro are frothing up the surface, as if the ocean had hiccups. The lava
is piling up on an underwater mountain. That the eruption is capable of firing
jets of water into the air shows that this mountain is growing — the center of
the eruption is approaching the surface. Geologists believe that new land could
soon emerge from the sea, and islanders are already looking for a name for the
new territory.
There are only 70 meters to go until the mountain reaches the
surface, experts from Spain’s National Geographic Institute (IGN) have reported.
But how big is the risk to nearby residents? Last weekend, hundreds of people
had to leave their homes in the southern part of El Hierro as streets were
closed. And locals can quite literally smell the danger — stinking sulfur fumes
are drifting across the ocean. The Volcanology Institute of the Canaries,
Involcan, has reported a three-fold increase in carbon dioxide levels — a
warning signal that further volcanic activity can be expected. –De
Spiegel
Source : The extinction protocol
