Showing posts with label Yemen volcano. Show all posts
Showing posts with label Yemen volcano. Show all posts

Monday, April 2, 2012

Earthquake Swarm and Possible Dike Intrusion at Krísuvík Volcano in Iceland

There is not a whole lot going on in the world in respect to new eruptions or volcanoes at this moment, however Iceland is always fascinating to watch. Today there was a swarm of quakes just SW of the Kleifarvatn lake, just south of the epicenter of Krísuvík volcano. The quakes were shallow, weak, and numerous, but the area is highly active, much like most of Iceland. Most of the quakes registered below a 1.0 magnitude, but were clearly seen on the many Icelandic seismic sensors. The are is home to many thermal vents, as well as hot springs, fumeroles, and fissures.

The last known eruption of Krísuvík volcano was in the 14th century (the 1500's). A few eruptions have taken place at this location after Iceland was settled, but nothing in recent times. It is probable that this swarm will not lead to an eruption any time soon, but Iceland sits on a spreading fault, so it is not a matter of if, but when this volcano will erupt again.

There are several volcanoes in Iceland that are expected to erupt at least within the next 10 years. Those are Katla, Askja, Grimsvötn (or Grimsfjall, Grimsnes), Hekla, and the Reykjanes Ridge, all of which show heightened seismic and thermal activity. However for most of these volcanoes, it is normal to display some kind of activity, and no eruption for any of these, save probably Katla and Hekla, are certain.

Icelands last major eruptions were from Eyjafjallajökull, and Grimsvötn. The Grimsvötn eruption, while spectacular to watch, was nowhere near as big a deal as the Eyjafjallajökull eruption which caused widespread economic damage due to flights to and from Europe being grounded for weeks because of the ash cloud it produced. The ash from Grimsvötn is much more coarse and larger grained than the very fine and powdery ash produced by the Eyjafjallajökull eruption, and thus fell to the earth quickly and did not get picked up by the jet stream.

The activity at Krísuvík can be attributed to a few causes. For one, Iceland is one of the worlds largest users of hydrothermal/geothermal energy, and regularly injects water into hot rocks to produce steam. This does sometimes cause swarms of quakes to occur, and it is rather hard to tell whether or not this could be related, but as the quakes happened on an active spreading fault, I suspect this is not the case, rather a small magma dike intrusion probably occurred.

Around the world most dormant volcanoes are sleeping or slowly rumbling away. Mt Etna did display some nice activity this weekend, but other than Etna's fireworks show, most active volcanoes showed relatively little activity during the month. Not good for us volcano bloggers out there to tell a story, but hey, the Earth does what it wants on its own time with little concern for my Google money! Hopefully this post is at least a good diversion! I'll post more as it occurs!

Monday, January 30, 2012

After Two Day Break, El Hierro Roars Back To Life



The last two days at El Hierro saw a calm stain on the water with few if any smoking lava stones, low harmonic tremor, and very little else. That ended this morning, when tremor again picked up, more smoking stones could be seen on the surface and emissions bounced back. El Hierro is not done yet.

                                                                                    


Images from El Hierro Telefonica/Movistar cam.

Today's current tremor. note the large increase over the last couple of hours.

El Hierro has been doing this off and on again eruptive cycle for weeks now, if not months. This is probably related to vent collapse and re-pressurization, leading to sporadic bursts in activity. Likely this will keep going on for quite some time. Tremor is QUITE strong today, so if you have the opportunity, you should check out the cam and keep your eyes peeled for some cool activity.


Thursday, January 5, 2012

Yemeni Volcano Jebel Zubair Erupts (VIDEO)




"Yemeni volcano Jebel Zubair has entered an eruptive phase (below)
Zubair Islands, Yemen
15.05 N, 42.18 E
summit elevation 191 m
Shield volcano
Jebel Zubair Volcano is located in the Red Sea, Yemen. Eruptions have formed the islands of Zubair, Centre Peak, Saba, and Haycock. 
Eruptions occurred at Saddle Island in the 19th century. Thee islands form the summit of a submarine rise. The volcanic cone is barren and rises 191 m above sea level.

2011 Eruption
A possible eruption occurred at Zubair volcano on 19th December 2011. Fishermen from Salif port city in the west of Yemen reported seeing an eruption with red lava rising to a height of 30 m. This was the first eruption the fisherman can recall from the area. Satellite images showed raised sulphur dioxide emissions close to the volcano on the following day"

From the Smithsonian GVP:

"The 5-km-long Jebel Zubair Island is the largest of a group of 10 small islands and submerged shoals that rise from a shallow platform in the Red Sea rift. The platform and eruptive vents forming the islands and shoals are oriented NNW-SSE, parallel to the rift. An early explosive phase was followed by a brief period of marine erosion, and then by renewed explosive activity accompanied by the extrusion of basaltic pahoehoe lava flows. This latest phase of activity occurred on the morphologically youngest islands of Zubair, Centre Peak, Saba, and Haycock. Historical explosive activity was reported from Saddle Island in the 19th century. Spatter cones and pyroclastic cones were erupted along fissures that form the low spine of Zubair Island."

(Now from me)

About two years ago now, another volcano on the same tectonic spread erupted, named Jebel al-Tair. That eruption was witnessed by a Coast Guard ship on patrol at the area. The island held a small Yemeni military contingent which was evacuated. At least two seven people died either swimming into the water in a panic to escape the lava, or from toxic gas. The new eruption is the island directly south of this volcano.

This could end up being a crustal trend in the area, although this is speculative. There are two other holocene volcanic islands to the SSE of Jebel al-Tair, and Jebel Zubair, which are morphologically fresh, although neither have a record of historical eruptions. The area is quite remote however, so it would not surprise me in the least if these islands had erupted behind our backs once or twice. Below is a screenshot from Google Earth of the Jebel Zubair volcanic island chain.
 

****UPDATE****

There seems to be some confusion as to whether or not this is Jebel Zubair, or Jebel al-Tair volcano. You can read about the confusion at Wired.com for yourself. Apparently, local reports place the eruption at Zubair, but satellite images are confusing. There does appear to be a steam/gas plume over Zubair, but satellite images show SO2 emissions over Al-Tair. It could even be that BOTH volcanoes may be showing signs of activity, which would not be entirely surprising. However, I have not known John Seach to post anything about an eruption unless he has confirmation somehow, so I honestly don't know who to believe at this point... interesting, nonetheless. 

Information from this part of Yemen and the Arabian rift is hard to come by. The area is not very populated, and the military outpost on Jebel al-Tair was destroyed in the last eruption, which was really one of the only "populated" (in quotes because 15 people does not a population make) island in the area. Reports will likely be few and far between, as far as Western Media.

*****UPDATE 1/5/12*****

Video footage via helicopter has been released!

Wednesday, December 28, 2011

Eruption At Jebel Zubair Confirmed, New Island Forms (VIDEO)

NASA has finally put the confusion to rest as to whether it was Jebel al-Tair or Jebel Zubair that was erupting in the Red Sea. NASA has posted new pictures of the new island as seen from space. Several news outlets have published the before and after pictures (link provided above), which clearly shows a brand new, steaming volcanic island in the Jebel Zubair volcanic island chain. This puts to rest any question as to what island was erupting.

The Red Sea Rift has been a bit more active lately with an eruption of Jebel al-Tair preceding the eruption at Jebel Zubair. There are no historical records of eruptions at Jebel Zubair that I am aware of, but I will check my volcano almanac tonight and this statement may change. Historical explosive activity was reported from Saddle Island in the 19th century (-GVP).

Enjoy the pictures of the new island! I can't help but be a bit miffed that I have been sitting and watching the eruption of El Hierro with the hopes of seeing the moment where the volcano breaks the surface, and then one goes and does it behind all our backs! This new island in the Jebel Zubair chain was built quite quickly, and its structure looks pretty solid from the pictures. Many new volcanoes are quickly eroded and reclaimed by the sea within days to decades, so it will be interesting to see if this is a permanent addition, or if it's going to be a temporary island.

Below is a link to good video from Yemeni TV of the new island erupting!

Video from Yemeni TV of the eruption

Pictured below are the before and after shots of Jebel Zubair:

Jebel Zubair Before Eruption

Jebel Zubair After Eruption