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Nearby earthquakes are opening up Africa's 'Gateway to Hell' volcano

Nearby earthquakes are opening up Africa's 'Gateway to Hell' volcano. Science & Technology World Website


NASA satellite imagery has spotted new cracks opening up near Africa's 'Gateway to Hell' – more officially known as the Erta Ale volcano in Ethiopia.

Scientists think nearby tectonic activity is causing large amounts of lava to spill out of the large, flat shield volcano, which features two lava lakes that have been bubbling and burning for decades.

It's one of the most spectacular sights in the natural world – not that you'd want to get too close, with lava temperatures inside these cauldrons reaching as high as 1,100 degrees Celsius (2,012 degrees Fahreneheit).

According to eyewitness reports, the lava lake levels have risen significantly over the past few weeks, producing "massive overflows" and "intense spattering" on top of the new fissures captured by NASA's satellites on the southeastern flank of the volcano, 7 kilometres (4.3 miles) from the summit.

The picture above was captured by NASA's Operational Land Imager (OLI) camera sat on board the Landsat 8 satellite: it combines natural colour and shortwave infrared light signals to identify smoke plumes as well as areas of increased temperature that would normally be invisible to the naked eye.

Where the infrared hot spots are marked in red on the image is where the overflowing lava channels are running.

These are the first flows beyond the volcano's crater that have been seen in a decade, according to Gezahegn Yirgu from Addis Ababa University in Ethiopia.

While the nearby area is uninhabited, lava could could continue to flow towards the town of Afdera, Nazret.com reports, and so needs to be monitored.

The 'Gateway to Hell' and 'Smoking Mountain' nicknames locals use for Erta Vale are well deserved. Set 613 metres (2,011 feet) above sea level, it's one of just five known volcanoes with molten lava lakes, and is the only one on record with two.

The site is part of the Danakil Depression in Ethiopia, where three tectonic plates are sliding away from each other as Africa and Asia move apart. In terms of average temperatures across the year, it's one of the hottest places on the planet.

Shield volcanoes like this are typically large and broad, with gentle slopes. They're primarily built around fluid lava flows, and are less explosive than traditional volcanoes because the chemical make-up of the basalt lava in them is less likely to get plugged up.

How much longer tectonic movement will cause disruptions to Erta Ale isn't clear, but the most recent reports suggest some of the overflowing has now stopped - which means the bravest photographers and tourists can venture back.

Previous visitors include Portuguese travel photographer Joel Santos, who made a dramatic video of his trip.

"Erta Ale is probably the most overwhelming, unreal and mesmerising sight one could see in a lifetime," he told MailOnline.


Shield volcano

Shield volcano. Science & Technology World Website

Mauna Kea, Hawaiʻi, a shield volcano on the Big Island of Hawaii


A shield volcano is a type of volcano usually built almost entirely of fluid lava flows. They are named for their low profile, resembling a warrior's shield lying on the ground. This is caused by the highly fluid lava they erupt, which travels farther than lava erupted from stratovolcanoes. This results in the steady accumulation of broad sheets of lava, building up the shield volcano's distinctive form. The shape of shield volcanoes is due to the low viscosity of their maficlava.

Etymology

Shield volcanoes are built by effusive eruptions, which flow out in all directions to create a shield like that of a warrior. The word "shield" has a long history, and is derived from the Old English scield or scild, which is in turn taken from the Proto-Germanic*skelduz, and related to the Gothic skildus, meaning "to divide, split, or separate". Shield volcano itself is taken from the German term Schildvulkan.


Erta Ale

Erta Ale. Science & Technology World Website


Ethiopia's "smoking mountain" is in one of the hottest regions on the planet and is home to two lava lakes  

Located in the Danakil Depression (or Afar Depression) in the Afar Region of northeastern Ethiopia, Erta Ale is one of the driest, lowest and hottest places on earth. Temperatures during the year range from 77°F to 118°F. The area is beset by drought, bereft of trees, and has little in the way of roads.

Known by the Afar as the “smoking mountain” and “the gateway to hell,” Erta Ale is a 2,011-foot-high constantly active basaltic shield volcano. It is one of only a handful of continuously active volcanos in the world, and a member of an even more exclusive group: volcanos with lava lakes. While there are only five known volcanos with lava lakes globally, Erta Ale often has two active lava lakes – making it a unique site.


Erta Ale. Science & Technology World Website


Erta Ale was discovered in 1906, making it the longest-known lava lake. For a lava lake to exist, the surface of the lake and the magma chamber below must form a constant convecting system, or the entire thing will cool and solidify. Beneath the ground surrounding Erta Ale is an enormous pool of active magma. The lake goes through cycles and will cool, form a black layer on top, and then suddenly convect back into liquid lava. Occasionally, due to pressure, “fountains” of lava will form, spewing lava in 6- to 13-foot-high plumes.

The volcano itself has erupted in 1873, 1903, 1940, 1960, 1967, and 2005, when it killed hundreds of livestock and forced thousands to flee. In 2007 lava flows once again forced evacuation and two people went missing, and were presumably killed.

Despite the harsh conditions, danger of volcanic eruption, and extreme heat, Erta Ale has become something of a tourist destination recently. Whereas in 2002 the area was accessible only by helicopter, today adventure tourism groups take trips to the volcano lakes and it is now possible to drive within 4.3 miles of the volcano.

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