A devastating earthquake/volcanic eruption leading to a landslide in the Canary Islands may only leave US East Coast residents a 6 hour warning.

With the recent earthquakes in the region picking up dramatically, the internet is going abuzz about the possiblities of a tsunami strike along the US East Coast.

Youtube reporter Mary Greeley examines these possibilities and the startling uptick in seismic activity in the Canary Islands in the video below. What would a large scale flank collapse and landslide mean to Americans?

The video at the bottom of the story outlines the alarming possibilities of such a catastrophic scenario.

Large landslides are inherent to the volcanic building process as material continuously accumulates until the point of slope failure (Holcomband Searle, 1991).

Debris avalanche deposits were for instance found in Hawaii (Moore et al., 1989; Robinson and Eakins, 2006) or at R´eunion Island (Cochonat et al., 1990; Oehler et al., 2004).

There is also clear geological evidence of past large paleo-submarine landslides of O(100 km3)volume around the Canary Islands (Spain). Masson et al. (2002) identified at least 14 large landslides, which have occurred on the flanks of the youngest Canary Islands (i.e., El Hierro, La Palma, and Tenerife) in the last one million years, with the youngest one, at El Hierro, being only 15,000 years old. Even much smaller debris flows can be quite destructive: the tsunami triggered by the 0.5 km3 Shimabara flank collapse in 1792 killed at least 4,000 people (Inoue, 2000).

Canary Islands, have the potential for generating vastly more destructive waves (i.e., mega-tsunami; Ward and Day, 2001). Such potentially catastrophic events may occur in average every 100,000 years in the Canary Archipelago. However, low probability does not necessarily mean low risk; so for proper tsunami hazard assessment, the consequences associated with such catastrophic events must be carefully estimated and modeled.

 

 

 

http://www.youtube.com/watch?v=PJhwKxy31Ck&feature=youtu.be

 

http://chinacat.coastal.udel.edu/nthmp/harris-etal-isope12.pdf

http://www.02.ign.es/ign/head/volcaSenalesAnterioresDia.do?nombreFichero=EHIG…

http://www.02.ign.es/ign/resources/volcanologia/txt/boletin_HIERRO.txt

http://en.wikipedia.org/wiki/Megatsunami Americas East Coast Megatsunami Canary Islands Geologists S. Day and S. Ward consider that a megatsunami could be generated during a future eruption involving the Cumbre Vieja on the volcanic ocean island of La Palma, in the Canary Islands. In 1949, the Cumbre Vieja volcano erupted at its Duraznero, Hoyo Negro and San Juan vents. During this eruption, an earthquake with an epicentre near the village of Jedy occurred.

The following day Rubio Bonelli, a local geologist, visited the summit area and discovered that a fissure about 2.5 km long had opened on the eastern side of the summit.

As a result, the western half of the Cumbre Vieja (which is the volcanically active arm of a triple-armed rift) had slipped about 2 m downwards and 1 m westwards towards the Atlantic Ocean. The Cumbre Vieja volcano is currently in a dormant stage, but will almost certainly erupt again in the future.

Day and Ward hypothesize that if such an eruption causes the western flank to fail, a megatsunami will be generated. La Palma is currently the most volcanically active island in the Canary Islands Archipelago.

It is likely that several eruptions would be required before failure would occur on Cumbre Vieja.

However, the western half of the volcano has an approximate volume of 500 km3 (5 x 1011 m3) and an estimated mass of 1.5 x 1015 kg.

If it were to catastrophically slide into the ocean, it could generate a wave with an initial height of about 1,000 metres (3,281 ft) at the island, and a likely height of around 50 metres (164 ft) at the Caribbean and the Eastern North American seaboard when it runs ashore eight or more hours later.

Tens of millions of lives would be lost as New York, Boston, Baltimore, Washington D.C., Miami, Havana, and many other cities near the Atlantic coast are leveled.

The likelihood of this happening is a matter of vigorous debate. The last Cumbre Vieja eruption occurred in 1971 at the southern end of the sub-aerial section without any movement.

The section affected by the 1949 eruption is currently stationary and does not appear to have moved since the initial rupture. Geologists and volcanologists also disagree about whether an eruption on the Cumbre Vieja would cause a single large gravitational landslide or a series of smaller landslides.

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