Sunday, November 13, 2011

IGN localized yesterday, Saturday, a total of 24 earthquakes in El Hierro with the greatest, a magnitude of 3.1

11/13/2011 ... 11:46 - Ministry of Economy, Finance and Security

* Two of them were felt by the population
* The Involcan shows a decrease in the emission of sulfur dioxide (SO2) into the atmosphere by the eruption of La Restinga underwater.


The National Geographic (IGN) has confirmed to the direction of Civil Protection Plan for Volcanic Risk Islands (PEVOLCA) during the day November 12 the number of earthquakes that were registered was, 24, two of which were felt by the population.

The main event registered yesterday and was felt by the population toaking place at 15:59 hours and reached a magnitude of 3.1 on the Richter scale. This earthquake is located at the NW of the town of Frontera, 3 kilometers from the coast and 19 kilometers deep.

The rest of the events recorded are located in the area of El Golfo (municipality of Frontera), aligned NNW / SSE from the sea to the center of the island forming two distinct groups: the first between 15-17 km and the second between the 20-24 km. In total, since the day July 17, 2011 11 522 events have been found.

Felt earthquakes were as follows: 10:55 pm, 16 km depth, magnitude 2.8, 15:59 hours, depth 19 km, magnitude 3.1

Tremor and distortion level

Moreover, the level of tremor showed frequent pulses of short duration (few minutes) all day yesterday, no major changes in the amplitude of tremor in the background. In the analysis of seismic data do not show evidence of a second source of tremor in the north.

As for the deformations, the monitoring stations in the east of El Golfo show a slight tendency toward the southeast in the last week, losing to the north deformation accumulated from the beginning of the eruption. In the other seasons maintaining the pattern of deformation of the last days.

Evolution of the stain at sea

During yesterday clearly was observed the head of the eruption, no bubbling or fine material was observed.

Diffuse emission of carbon dioxide


Scientists at the Institute of the Canary Islands volcanological (Involcan) have confirmed the direction of PEVOLCA that there has been a decrease in the emission of sulfur dioxide (SO2) into the atmosphere from the eruption is taking place underwater in the South La Restinga.

The results show that the emission of sulfur dioxide (SO2) into the atmosphere increased from 109 ± 19 tons per day on Sunday November 6 to record non-quantifiable values ​​on Saturday November 12 since they are below the limit detection of the analytical methodology used (<2 tonnes per day). The measurements made on Monday November 7 and Tuesday, November 8 yielded an emission rate of 36 ± 9 and 28 ± 15 tons per day of sulfur dioxide (SO2), respectively. Later on Thursday, November 10 quantifiable values ​​were recorded lower emissions of sulfur dioxide (SO2) during the past week, 7 ± 6 tons per day. These results reflect an emission rate of sulfur dioxide (SO2) relatively lower than those normally recorded in volcanic systems subaerial eruptive phase as a result of a neutralization reaction between acid volcanic gases and seawater by alkaline nature that part of the sulfur dioxide (SO2) emitted by the submarine volcano south of the Restinga not reach the atmosphere and contributes to lowering the pH of seawater as well have been reflected by measurements taken by research vessels "Professor Ignacio Lozano "and" Ramon Margalef "of the Canary Institute of Marine Sciences (ICCM) and the Spanish Institute of Oceanography (IEO), respectively.

Recommendations

The direction of PEVOLCA recommends that people follow the recommendations made for the earthquakes and be attentive to the instructions of the authorities, both through the media, the telephone number for citizens of the Canary Islands, 012, and page Canary Islands Government website, www.gobiernodecanarias.org / DGSE / sismo_hierro.html and the Cabildo de El Hierro, www.emergenciaselhierro.org.

No comments:

Post a Comment

Note: Only a member of this blog may post a comment.