[/quote]quote:El Hierro’s Volcanic/Seismic Past
El Hierro is situated in the most southwestern extreme of the Canaries. The island was formed after three successive eruptions, and consequent accumulations, the island emerged from the ocean as an imposing triangular pyramid crowned by a volcano more than 2,000 metres high.
The volcanic activity, principally at the convergence of the three ridges, resulted in the continual expansion of the island. A mere 50,000 years ago, as a result of seismic tremors which produced massive landslides, a giant piece of the island cracked off, crashed down into the ocean and scattered along the seabed. This landslide of more than 300km3 gave rise to the impressive amphitheatre of the El Golfo valley and at the same time caused a tsunami that most likely rose over 100 metres high and probably reached as far as the American coast.
twitter:
quote:2013-12-28 13:11 UTC
The first satellite image (Modis Terra satellite) has too much clouds above yesterdays epicenter area to determine color differences in the ocean (the ocean is colored light blue on this location, but these spots are probably clouds). There is another satellite image coming shortly from the Modis Aqua satellite. So hang on to see the latest details.
Click on the link to see it in full size (your computer will need some time to load it!)
Zoals eerder gezegd is dat La Palma idd. Daar heb je de Cumbre Vieja vulkaan die voor het laatst in 1971 was uitgebarsten. In 1949 zorgde dat voor een verzakking van een deel van het eiland, dus het zaakje zou aardig instabiel kunnen zijn.quote:Op zaterdag 28 december 2013 11:37 schreef Scrummie het volgende:
Dit is toch het eiland dat een mega tsunami veroorzaakt als er wat afbreekt ofzo?
twitter:etnaboris twitterde op zaterdag 28-12-2013 om 18:32:04 @CultureVolcan @magmatters Radon is not a gas that comes from the magma, but which comes from the uppermost few meters of the soil (1/2) reageer retweet
En waar is dit op gebaseerd?twitter:etnaboris twitterde op zaterdag 28-12-2013 om 18:32:45 @CultureVolcan @magmatters Radon is released when the ground is subjected to fracturing (induced, e.g., by inflation or seismicity) (2/2) reageer retweet
twitter:teideano twitterde op zaterdag 28-12-2013 om 02:14:39 222Rn measurements at one of our stations in El Hierro.Precursory activity b4 the earthquake? #volcano #science http://t.co/9prar7IssE reageer retweet
twitter:teideano twitterde op zondag 29-12-2013 om 03:03:18 http://t.co/gzWAOpC28c Amazing video of El Hierro #quake #volcano #geology #nature #wow reageer retweet
twitter:teideano twitterde op zaterdag 28-12-2013 om 02:55:54 Multiple Rockfalls at El Hierro. #volcano #earthquake #geology via Inma Guedes,http://t.co/007CcpwzCm http://t.co/oCBYhUxN71 reageer retweet
twitter:teideano twitterde op zondag 29-12-2013 om 11:52:09 Aftermath of the 5.3 quake at El Hierro. Pic from Yera Ds. #volcano #geology #nature http://t.co/riu9tyhFvj reageer retweet
twitter:teideano twitterde op zondag 29-12-2013 om 11:53:26 Aftermath of the 5.3 quake at El Hierro. Pic from Yera Ds. #volcano #geology #nature http://t.co/tftuqiR4Yb reageer retweet
twitter:VolcanoReport twitterde op maandag 30-12-2013 om 09:51:31 El #Hierro #Volcano Crisis: New data showing changing (but still present) deformations - http://t.co/8YJ4WxbHdK http://t.co/bfjOAPmCNM reageer retweet
twitter:teideano twitterde op maandag 30-12-2013 om 11:00:14 El Hierro still inflating, no seismicity detected. Up to 8.3 cm at some sites, strange behaviour. #volcano #geology http://t.co/eQU9rI7tEx reageer retweet
Plaatje van alle bevingen tot nu toe uit de OP bijgewerkt. Laat nu ook van augustus tot nu toe zien.quote:2013-12-30 08:03 UTC
NO more earthquakes, very calm graphs but again spectacular deformation charts.
Deformations are giving a totally changed pattern this morning. The Southern areas are subsiding. The eastern central area is stabilizing BUT the western central and northern areas are inflating (western area very strong). HI10 (El Julan) has no data for the second day in a row. The changing deformation pattern shows the biggest magma movement below the island concentrating in the El Golfo area (Sabinosa to Frontera) and is an additional sign that the crisis isnt over yet.
The strongest deformation today is noted in Sabinosa (GPS station HI03) where the ground was lifted 3 cm in less than 24 hours. The station HI04 (slightly west of HI03 (see map) has however stabilized data.
This crisis will only end when the deformations are stabilizing everywhere.
quote:2013-12-31 08:52 UTC
What we had expected last night was confirmed this morning by the new deformation data : a general subsidence (deflation) of the island (remark : a couple of signals – HI01 and HI10 – were not updated).
Frontera had a 1 day deflation of 4 cm!.
Yesterday we saw the last tremor disappear from various seismographs. Tremor is the indication that magma is moving somewhere below the island.
The 2 new earthquakes have no special meaning as they will be probably generated by deformation stress and not by magma stress or movement. This will certainly happen more the next few days.
How long will it take to the next crisis ? Nobody knows as it can happen tomorrow or next year, but scientists are convinced that more activity periods will follow.
We were once again happily surprised by the many people following this crisis via earthquake-report.com. We will continue this report also in the future. Please continue to send a comment when you see something irregular on one of the seismographs.
quote:2014-01-01 13:23 UTC
Renewed increasing tremor is visible in the El Golfo area (TAB en TAN seismographs). Remember that we mentioned this morning that HI04 Sabinosa area GPS station had an increase of at least 2 cm during the last 24 hours.
2014-01-01 10:44 UTC
4 earthquakes since our latest update. The M2.1 at 3 km depth earthquake was located to the south of La Restinga in the Las Calmas sea
Ecxept for the HI04 GPS (Sabinosa) who shows a lifting of 2 cm, almost all the other stations stabilizes based on the new IGN deformation data.
Link to graph of HI00; HI08, HI09 and HI10
Link to graph of HI01, FRON, HI02, HI03 and HI04
1252804 01/01/2014 23:12:31 27.6679 -18.2876 17 1.9 4 SW FRONTERA.IHIquote:2014-01-02 09:00 UTC
NO new deformation data yet.
1 earthquake listed by IGN
Some tremor, who started yesterday, is still present at the Western El Golfo stations.
twitter:
Alleen meetstation HI09 (La Restinga) lijkt nog iets of wat om hoog te gaan. Alle andere lijken te dalen.quote:2014-01-03 13:25 UTC
Another special event took place very recently, 2 relatively shallow earthquakes (9 and 10 km deep) in a new area to the east of La Restinga. The first one being a strong M2.8 earthquake, the second (aftershock?) a M1.8 earthquake 1 minute and 44 seconds later. Especially the location is intriguing us.
En dan de melding van vandaag...........quote:2014-01-05 20:19 UTC
Our yesterday’s update was unfortunately not published.
Todays picture is somewhat like the preceding days. Almost no earthquakes, subsidence (even strong) in some parts again (weak) lifting in other parts.
Some tremor is still present in some parts of the island (probably due to a very sensitive scale). When we see this kind of tremor, and if the weather is not the source, this is mostly followed by a weak or even stronger lifting. We are curious what the current situation will generate on tomorrow’s deformation.
The picture below is from the lighthouse seismograph. As the amplitude on every seismograph is different it is hard to say what exactly happens.
As long as the deformations (see links below) are not stabilized, we will continue to follow up the situation on a daily basis (in fact many times per day)
quote:2014-01-06 10:15 UTC
NO earthquakes, but almost all the GPS deformation data slightly up. Tremor continues to show at the same stations than yesterday but is decreasing strongly the last couple of hours.
twitter:teideano twitterde op maandag 06-01-2014 om 16:20:37 El Hierro 2013 seismic activity. 4120 earthquakes located. #geology #science #nature Source: http://t.co/JDFqxgRY5n http://t.co/uqYeVtsBFy reageer retweet
twitter:teideano twitterde op maandag 06-01-2014 om 16:28:45 339 were at least >M3, 31 >M4, 7 >M4,5 and 1 M>5. We can say it was an interesting year. #geology #volcano #nature http://t.co/EKmzyDMZXz reageer retweet
het zwakt dus echt af.quote:2014-01-07 08:30 UTC
Vertical deformations are down all over the island again.
Seismographs are showing the same amplitude than yesterday evening although the waves have decreased already somewhat (6 to 4 meter average)
No new earthquakes.
twitter:teideano twitterde op donderdag 09-01-2014 om 10:19:10 #weather #nature Amazing Hailstorm at Fasnia, Tenerife, 500m a.s.l. Canary Islands http://t.co/5EydXYtNez reageer retweet
twitter:teideano twitterde op donderdag 09-01-2014 om 14:23:07 #alertacanarias #FMACanarias #meteo La borrasca, sobre Canarias ahora mismo, preciosa situación http://t.co/dI6xmZX1kD reageer retweet
quote:2014-01-12 09:38 UTC
Time to make a new update, just to say that the activity below the island has come to a standstill. Only 2 earthquakes since our latest report of earthquakes (1 of these 2 in the region of the M5.1 earthquake relatively far out in the Ocean).
The amplitude of the seismograms is back to very low levels. The increased amplitude the last couple of days was generated by a stormy sea. On some seismographs one could see clearly the tides !
Deformations show small ups and downs but are in average constant.
quote:2014-01-13 06:09 UTC
The activity on all the Canary Islands seismographs are due to the very strong earthquake out of the coast of Puerto Rico earlier today. It has NO link at all with the El Hierro activity. Thanks for reporting in the comments though.
quote:2014-01-18 20:02 UTC
We are noticing increasing tremor in the ctan and cjul seismographs this morning (Ctan and Ctab have both been stopped or hided from public viewing by IGN). We do not think that the current increase is due to bad weather or increasing waves although a slight increase in waves occurred earlier. NO additional earthquakes. We will keep an eye the following hours and days to find out eventual changes.
2014-01-18 08:55 UTC
THE news the last couple of hours at El Hierro was the report of AVCAN that a lot of pumice was collected the last 24 hours in the waters and at the beach of Arenas Blancas at the West Coast of the Island. The pumice will have to be analyzed by specialized laboratories to find a clue where it comes from. This will not be easy at all as the instruments are not showing any traces of eruptive activity at this moment besides a weak increase in tremor on a couple of seismographs (which can also have been caused by the waves).
We do not know whether the strong subsidence of some GPS stations are related to the newly found pumice.
twitter:teideano twitterde op zaterdag 18-01-2014 om 11:26:43 Deformation at El Hierro again on the rise. The game is not over yet. #volcano #science #geology #nature http://t.co/VWJpEIuryV reageer retweet
quote:2014-02-05 10:47 UTC
This is the seismicity below the island since our last update. A limited number of daily earthquakes after all.
twitter:teideano twitterde op maandag 10-02-2014 om 12:09:41 Terremoto de 3,5 grados en la isla de La Palma, Canarias, sentido por parte de la población. #ciencia #naturaleza http://t.co/PSEIjjxcbQ reageer retweet
quote:Translation: Earthquake of 3.5 degrees on the island of La Palma, Canary Islands, felt by the population
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