Giant volcano

The whole island of Ambrym has been shaped by the enormous basaltic Ambrym volcano. Sometimes around 190 AD (or somewhat later… or before this… exact date is not known) here happened a giant volcanic eruption which created the present-day Ambrym caldera which is some 12 by 8 km large.

Later in this caldera rose several craters – two larger ones (Benbow and Marum) and three smaller ones.

Ambrym is one of the world’s most active volcanoes up to this day. Its eruptions often are disastrous and local people from time to time (e.g. in December 1913) are forced to flee from the island.

According to a local legend, one of the villages has a special power over the volcano. They have magical stones hidden in the ground – these stones can cause an eruption.

Lava lake in Mbwelesu Crater

The research history of the Ambrym volcano is fairly short – only in the late 19th century, it was first climbed. Several times there have been observed lava lakes. For several decades from the 1990ies until December 2018, there existed two lava lakes – one in Benbow Crater and one in a smaller side crater of Marum – Mbwelesu Crater.

In August 2018 there were even three lava lakes – a third one appeared in the Niri Mbwelesu crater around January 2018.

The lava lake in the Mbwelesu crater could be observed right from the rim of the crater. The rims of the crater are near vertical – one should be very careful here.

The lava lake was small but absolutely fascinating. It had constant lava fountains rising up to 30 m high, and the small lake had a constant movement, mesmerizing the visitors. It was even more impressive during the night. There were few places on Earth with similar experiences.

After a powerful eruption and several earthquakes, all the lava lakes of the Ambrym volcano have disappeared. We do not know if they will return…

Mbwelesu Crater (Marum Crater) is included in the following article:

Giant volcano

The island of Ambrym is a volcano – the whole island has been shaped by the basaltic Ambrym volcano. Sometimes around 190 AD (or somewhat later… or before this… exact date is not known) a giant volcanic eruption created the present-day Ambrym caldera which is some 12 by 8 km large.

Later in this caldera rose several craters – two larger ones (Benbow and Marum) and three smaller ones.

Ambrym is one of the world’s most active volcanoes to this day. Its eruptions often are disastrous and local people from time to time (e.g. in December 1913) are forced to flee from the island.

Around the crater grows a lush tropical forest with gorgeous orchids. Orchids grow in the caldera as well. Closer to the craters, though, the land is empty due to frequent eruptions and acid emissions.

One should visit the volcano at certain times of the year with experienced local guides. There are cultural restrictions – many places are subject to seasonal taboos.

Acid rain

Acid rain from the craters of Ambrym is fairly common. Thus, in March 1979 from Benbow Crater rose a very destructive cloud of acid rain with sulfuric acid. Within 24 hours much of the vegetation in the southwest part of the island was lifeless, and water supplies were contaminated. Some people got acid burns.

In November 2002 acid rain eliminated mango fields on the west coast. Frequent acid rains have caused a lack of suitable groundwater and locals are in a dire need of fresh water.

Lava lake in Benbow Crater

Over the last century, lava lakes in the craters of the Ambrym volcano have been observed several times. For several decades from the 1990ies until December 2018, there existed two lava lakes – one in Benbow Crater and one in a smaller side crater of Marum – Mbwelesu Crater.

In August 2018 there were even three lava lakes – a third one appeared in the Niri Mbwelesu crater around January 2018.

The lava lake in the Benbow crater could not be seen from the rim of the crater and visitors had to descend in the crater and some dared to approach up to 100 m distance from the lake. But this trip hard was rewarding – the lava lake offered a view that is very, very rare on Earth.

The lava lake was rather small, some 40 by 30 m large. But it was in constant movement with lava fountains and waves. Visitors stood at the crater and it was hard to leave…

After a powerful eruption and several earthquakes, all the lava lakes of the Ambrym volcano disappeared on December 16, 2018. We do not know if they will return…

References

1. Ambrym volcano. Accessed on June 10, 2019
2. Smithsonian Institution, National Museum of Natural History. Global Volcanism Program. Ambrym. Accessed on June 10, 2019

Benbow Crater is included in the following article:

Kilauea – one of the most active volcanoes in the world

Until recent times geologists thought that Kilauea (correct – Kīlauea) is a side crater of another volcano – the giant Mauna Loa whose caldera is some 33 km to the north-west.

Now it has been proved that Kilauea is a separate volcano that has its own plumbing of magma extending more than 60 km deep.

Kilauea with its numerous vents and side craters have formed the south-eastern part of Hawaii Island. It is some 1.2 km tall, with gentle slopes – a typical shield volcano. The landscape around the summit of the volcano is barren, even desert-like: the frequent lava flows and sulfurous smogs (called – vogs) have eliminated most of the vegetation.

The volcano has more than 10 craters that like a row of bullets from automatic weapons have pierced the island. The most famous and most interesting is the westernmost crater – Kilauea Caldera. This is a magnificent 4 by 3.2 km large crater with walls that are up to 120 m high.

In the western part of this caldera is located a deep pit – Halemaumau Crater or, a more correct form – Halema’uma’u Crater – “house of the ‘āma’u fern”.

Halemaumau Crater and its lava lake

Halemaumau crater until the eruptions of 2018 was some 770 by 900 m large. The depth of it is unknown – for the most part of the time since the discovery this pit has been filled with a lava lake. And lava lakes… well, these easily could be the deepest lakes in the world, extending below the crust of the Earth.

There are very few volcanoes in the world that have permanent or near-permanent lava lakes – some ten places around the world. The lava lake of Halemaumau Crater though is not exactly permanent… because now, in 2019 it’s gone.

At some periods of the time Kilauea volcano had one more lava lake some 18 km to the south-east, in another crater named Pu’u ‘Ō’ō. Here such a lake existed, for example, in 1986 – 1997 and 2011 – 2018. Currently (in 2019) there is no lava lake in this crater either.

History

Of course, Hawaiians knew about the volcano since their arrival – but there are no written sources. It is known that in 1790 there was a terrible, explosive eruption that killed people.

The first known description by Europeans is left by William Ellis, a missionary and geologist in 1823. It seems, already then there was a lava lake in the crater. Mark Twain observed the lava lake in 1866 and was enchanted by the incomparable beauty of this place.

In 1912 geologist Thomas Jaggar founded an observatory here. This area in 1916 became Hawaii Volcanoes National Park and step by step Kilauea turned into a scientific base for the exploration of geological processes as well as a top tourist destination as well.

There is much to explore and to see around the Kilauea volcano. Since 1952 there have been at least 34 eruptions, each of them different.

Eruption in 1983 – 2018

The latest eruption started in 1983 and with some periods of silence continued up to 2018.

The lava lake in the crater changed a lot numerous times during this time period. For example, in April 2015 lava spilled over the rim of the crater on the floor of the caldera covering it with a 9 m thick layer. By late 2016 it was one of the largest lava lakes in the world, some 250 m by 190 m large.

After repeated floods of lava in May 2018, everything changed to the opposite. The level of the lava lake dropped and it disappeared at least 340 meters down in the crater. This was accompanied by powerful explosions and local earthquakes, from the crater rose clouds of hot ash and toxic gases. The walls of the crater started to collapse and the lake is not visible anymore.

This coincided with another event: lava started to pour out from the ground some 40 km to the east, in Leilani Estates. This idyllic Hawaiian village and other villages and resorts in the area were attacked by lava, which soon reached the sea, changing the coastline and covering with lava some 35 km². Most likely the disappearance of the lava lake in Halemaumau is linked to this flood of lava.

The area was closed for visitors from May 10 to September 22. Now, in 2019 the eruption has stopped but the landslides around the crater continue – even the building of Jaggar Museum is endangered and abandoned. This was the largest eruption of Kilauea over the last 200 years.

In August 2019 it was reported that on the floor of the crater has appeared a rather common lake, consisting of… water. This water is fairly hot – around 70° C. (3)

Legends and ghost stories

Halemaumau Crater is a very important sacred site for Hawaiians and traditional offerings are made here up to this day.

According to the local beliefs, Halemaumau Crater is the abode of Pele – Hawaiian goddess of fire and volcanoes. This goddess created the Hawaiian Islands and after lengthy wanderings and numerous battles found peace in this crater. Hawaiians call this place also Ka Piko o ka Honua – the Navel of the World.

People tell also that Pele appears to some people before dangerous eruptions. She is either an old woman or a young, beautiful lady in a red robe (muumuu) and accompanied by a small, white dog. Of course, one should be polite and help the goddess.

A weird silhouette has been noticed in several images of the eruption of Kilauea in 2018 and earlier. The silhouette of a black woman with glowing eyes is seen in a photograph of a lava stream falling in the sea.

One more belief of Kilauea: guests should not take anything from here – the stone from the summit of the volcano (or even anywhere on the island) will bring unhappiness at home. Reportedly, many visitors sent back to Hawaii such souvenirs after their families and houses have been hit by repeated calamities. Reading their letters is quite impressive.

References

1. Chronology of Kīlauea’s summit eruption, 2008 – 2017, USGS website. Accessed on May 22, 2019
2. Return Lava Rock to Hawaii!, Volcano Gallery. Accessed on May 22, 2019
3. Scientists: Water on floor of Halemaumau Crater is hot. Really hot., Hawaii News Now. Accessed on August 08, 2019

Halemaumau Crater is included in the following article:

Geological history

Mount Erebus has formed above Erebus hotspot – a kind of “burner” through the Earth’s crust. As the continental plates move around, the “burner” burns through, creating a chain of volcanoes. These volcanoes become extinct as they “float” away from the hotspot. Consequently, new volcanoes emerge in places where before was just plain land.

The formation of Erebus started some 1.3 million years ago. Since then the volcano has reached a height of 3,794 m above the sea. Thanks to this giant mountain Ross Island is the 6th highest island in the world. An ice sheet connects the island to the mainland. This ice is stable enough to have a permanent airfield on it.

On the same Ross Island are three more volcanoes: Mount Terror, Mount Bird, and Mount Terra Nova. None of them is active.

Description of Mount Erebus

Mount Erebus erupts continuously since its discovery in 1841. Thus it is the most active volcano in Antarctica.

Erebus is also the southernmost active volcano on Earth and the second-highest volcano in Antarctica. The highest is Mount Sidley – a dormant volcano that rises 4,181 – 4,285 m high.

At the summit of the volcano is a 500 by 600 m large and 110 m deep crater. In this crater is one more – an inner crater that is some 250 m wide and 100 m deep. In this inner crater is a lava lake – one of the few such lakes in the world. It is filled with phonolitic lava. In fact, Mount Erebus is the only volcano in the world that erupts this kind of lava currently.

Lava lake

If the weather lets see through the fumes, visitors can admire the glow of this lake from the rim of the crater. The lava lake of Mount Erebus has existed since the discovery of the volcano (and, most likely, before this), but it has constantly changed.

Thus, during the 1970ies the lava lake was some 130 m long and had an oval shape. Then, in 1984 – 1985 the volcanic activity increased and the glow of lava was visible from a distance of some 70 km. During this time most of the lava lake “froze” – solidified. Nevertheless, Erebus threw volcanic bombs with a diameter of up to 10 m up to 1.2 km far!

A small lava lake with a diameter of some 15 m appeared in late 1985. Then, in the late 1980ies, researchers observed up to three smaller lava lakes.

Lava lake or several lakes existed in the crater in the 1990ies and in the 21st century. In 2010 – 2016 volcano had two lava lakes.

Other wonders of Mount Erebus

In the volcanic bombs of the unique phonolitic lava have formed so-called Erebus crystals – unusually large crystals of anorthoclase. Visitors can find them around the summit of the volcano. Although these crystals are not especially beautiful they are a mineralogical rarity.

Other peculiarities of this volcano are up to 12 m high ice towers. These natural wonders were created by fumaroles – natural exhausts of warm gases and vapor. Vapor freezes in the Antarctic climate, gradually building the ice tower around the fumarole. In the middle of this tower is a hole – well and gases escape through the upper end of the tower. Volcanic fumaroles have made similar ice towers in several more locations around the world.

The volcanic heat of Mount Erebus has created also a unique ecosystem to the north from its summit, at Tramway Ridge. Here in the heated soil live mosses and microorganisms, over millennia cyanobacteria have created a weird mat. Under this mat has developed a habitat with archaea. These microorganisms most likely are unique to Tramway Ridge.

Discovery and research

Sir James Ross discovered Ross Island and Mount Erebus on January 27, 1841. He named the volcano after his ship HMS Erebus – a military ship. “Erebus” is a Greek deity of darkness and Brits considered this to be a fine name for military ship and… also a volcano!

As Ross Island is the southernmost island to be reached by ship, it served as a base for early expeditions to Antarctica. And, up to this day here is the largest Antarctic settlement – McMurdo Station (United States) as well as Scott Base (New Zealand).

The volcano was first climbed in 1908 by a team of the Nimrod expedition (British Antarctic Expedition). The expedition was led by Sir Ernest Shackleton and the leader of these brave climbers was Sir Edgeworth David. They climbed for five exhaustive days.

As the volcano is fairly easy to access (By Antarctic standards), it has been much explored. Thus, until 2016 the New Mexico Institute of Mining and Technology (USA) had here Mount Erebus Volcano Observatory. They created a summer field camp not too far from the summit, at a height of 3,400 m. Also, around the volcano was a network of seismic stations.

References

1. Mount Erebus Volcano Observatory, New Mexico Tech. Accessed on April 22, 2019.
2. Erebud, Smithsonian Institution, National Museum of Natural History, Global Volcanism Program. Accessed on April 22, 2019.

Mount Erebus is included in the following article:

Legends of Nyiragongo

This unusual volcano is a hero of diverse local beliefs. Some legends tell about weird beasts and ghosts living in the crater. Others tell about a mythic fight between two powerful spirits – Nyiragongo and Ryang’ombe, eternal enemies. Ryang’ombe lives in Muhavura volcano. Nyiragongo lived in Mount Mikeno. Ryang’ombe cut Mount Mikeno into two pieces and harassed Nyiragongo to the present-day Nyiragongo volcano, cut off the peak of the volcano, and threw Nyiragongo in it. Then he piled hot stones over Nyiragongo and left him there.

Since then the better behaved (or – more evolved) spirits reside in the abode of Ryang’ombe, while the evil and more profane spirits live in Nyiragongo.

Crater with world’s largest lava lake

Mount Nyiragongo is a giant stratovolcano. Most of the mountain is covered with tropical forest but closer to its summit instead of a forest come shrubs and then – alpine meadows. And then to the eyes of a visitor opens a grand view into the giant crater.

The crater of Nyiragongo is some 1.2 – 1.3 km wide and very deep. It has two lava benches – two floors. The upper bench is at the height of some 3,175 m, some 300 m below the summit. The lower step is at the height of approximately 2,975 m, some 500 m below the summit. This lower step contains a rare natural phenomenon – a nearly permanent lava lake.

This lake is constantly changing. At some moments it rises, flooding the lower bench and then also the upper bench. Such floods of molten stone happened in January 1977, when the lake rose to the level of some 3,250 m – then this hellish lake was some 600 m deep!

This lava lake is fascinating – it seems to be alive, in a constant movement. Unusual natural phenomena have been observed here. Thus in 1982 (after the lava lake poured out from the crack on surrounding lands), the lake started to renovate itself… by mighty fountains of lava! This was the most spectacular process with two 5 – 10 m tall lava fountains at the bottom of the crater which soon increased to a huge, 150 m wide and up to 50 m high dome – fountain.

Another phenomenon started around 2010: the lava lake rose above the crater floor but did not expand on the floor of the crater. The lake created a rim of hardened lava and rose above the floor of the crater as a unique bowl. Streams of glowing lava were flowing over this rim, providing unique, unforgettable sight.

The lava lake has been here almost constantly since 1948 when the legendary vulcanologist Haroun Tazieff descended into the crater and proved its existence. But we can be sure that it is considerably older because local people noticed the hellish glow of the lake in night skies well before this. And the lake continues to exist also in 2019.

The black heart of Africa?

Since the start of observations in 1882, the volcano had at least 34 eruptions. Sometimes these eruptions have continued for years, thus the current eruption started in 2002 and lasts up to now (2019).

Mount Nyiragongo definitely is not a common volcano and it is extremely dangerous in several ways.

The worst danger has been the lava of this volcano. This is highly unusual, alkali-rich lava, consisting of melilite nephelinite. And this is treacherous, deadly lava. On the steep slopes of Nyiragongo, it may flow at a terrible speed: up to 60 km per hour (some sources state even 100 km/h)!

And Mount Nyiragongo loves to let it flow… Thus, in January 1977, when the lava lake reached its fantastic depth of 600 m, the rim of the crater fractured and a fearsome flood started. The whole lake gushed out in some 30 minutes, covering forests, villages and after 20 minutes reaching Goma city. Then it killed at least 70 people.

In 2002 even more spectacular and destructive eruption took place – the side of the volcano cracked again and a 13 km (!) long fissure opened. The earth opened up to the outskirts of Goma city near Lake Kivu and lava gushed out from the fissure. Op to 1 km wide and 2 m thick stream of molten stone flew through Goma city, covering some 15% of the city. The stream of lava covered part of the runway of Goma airport and poured into Lake Kivu.

Around 245 people died and some 120,000 people became homeless. After the eruption followed many earthquakes and destroyed many buildings in the area.

Another danger of Mount Nyiragongo is mazuku – seeps of carbon dioxide. Such gas seeps appear unnoticed and from time to time suffocate people, especially in rooms and calm places where the wind does not disperse the gas. Mazuku cannot be seen or smelled. Somewhat less dangerous are the acid rains around the volcano which cause loss of vegetation.

As if the fury of nature is not enough, around Mount Nyiragongo for decades continue, possibly, the most horrifying wars of our times. From time to time the area is closed for tourism – even military guards cannot warrant the safety of guests. Meanwhile millions of people around the volcano live in extreme poverty. It seems the evil spirits of Nyiragongo are governing here indeed.

References

1. Nyiragongo, Smithsonian Institution, Global Volcanism Program. Accessed on March 16, 2019

Mount Nyiragongo is included in the following article:

“Smoking mountain”

Erta Ale – the most active volcano in Ethiopia – has formed over the East African Rift system. Here the crust of Earth is spreading: literally, the Earth is opening here and magma is close to the surface.

The volcanoes here are not cone-shaped giant mountains that from time to time explode, killing all around them. Erta Ale is a typical basaltic shield volcano with very gentle slopes. This mountain is some 50 km wide and rises approximately 700 meters above the Danakil Depression. The caldera of Erta Ale is complex, approximately 1.7 km long and 0.6 km wide, with several crater openings in it.

Most active are two of these craters – one in the north and one in the south. The famous lava lake is in the southern crater, although sometimes lava lake has been reported also in the northern crater.

Eruptions of Erta Ale

Due to its remote location, Erta Ale has been seldom visited by scientists and we know little about its activity in the past, but there are reports about eruptions in 1873, 1903, 1904, 1906, 1940, and 1960. It is very likely that there were eruptions also in between – or maybe the eruption has continued all the time.

The current eruption started in 1967 and has not stopped since then. Since this time has existed the lava lake, which sometimes overflows the southern rim. There open also cracks in other locations and lava pours out: thus in January 2017 some 7 kilometers south of the lava lake opened a new fissure and huge amounts of lava covered the ground.

Eruptions of such basaltic volcanoes are comparatively silent but nevertheless, dangerous. Basaltic lava could flow quite fast and the gentle slopes of the volcano may lead to unexpected turns of lava flows.

Even if Erta Ale is located in a sparsely populated area, its eruptions may create havoc in local communities. Thus, on 25th September 2005 eruption forced thousands of people to evacuate and killed livestock. Another eruption in August 2007 again forced the evacuation.

Lava lakes

Lakes of lava are very rare on Earth – and Erta Ale has one of the best ones and nowhere else has it existed that long as here. It is known that lava lake in the southern crater exists since 1967 but it is highly likely that it existed here well before this. There have been reports also about another lava lake in the northern crater in earlier times.

The lava lake is circular, some 50 meters in diameter. In the daytime, it is black, molten basalt with visible cracks of deep-red lava. Meanwhile, at the night it turns out that the whole surface of the lake is emitting a quite strong glow. The sight of the lake is fascinating – lava is constantly changing.

Sometimes the level of lava rises and the lake spills over its rims. At such times the glow of the lava in the night is seen far away from the summit – this is an unusual spectacle of the forces of nature!

Dangerous tourism

This area is one of the world’s most remote and inhospitable locations and travel to the volcano is dangerous and rather difficult. This is further complicated by the unrest of local people – there have been cases when tourists and scientists have been attacked and killed. Now the tourist groups are accompanied by a military escort.

Nevertheless, Erta Ale has a constant flow of tourists, uniting this trip with the visit to one more unique natural landmark – the colorful Dallol hot springs and geysers.

References

1. Erta Ale volcano, Volcano Discovery. Accessed on February 7, 2019
2. Fissure Eruptions on Erta Ale, NASA Earth Observatory. Accessed on February 7, 2019

Erta Ale is included in the following article: