Earthquakes, volcanic eruptions in Hawaii


This 6 May 2018 video is called Earthquakes And Eruptions On Hawaii’s Big Island.

How long will Kilauea’s eruption last? A volcanologist tackles that and other burning questions about the Hawaii volcano. ByCarolyn Gramling, 5:16pm, May 8, 2018.

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How volcanism converted Iceland to Christianity


This 2017 video is about Ófærufoss waterfall in Iceland. It says abput itself:

Located near Eldgjá in central Iceland. Until the early 1990s a natural bridge spanned the falls, but it collapsed from natural causes. Pronunciation “oe-fai-ru-foss”.

a href=”https://www.sciencedaily.com/releases/2018/03/180319090740.htm”>From the University of Cambridge in England:

Volcanic eruption influenced Iceland’s conversion to Christianity

March 19, 2018

Memories of the largest lava flood in the history of Iceland, recorded in an apocalyptic medieval poem, were used to drive the island’s conversion to Christianity, new research suggests.

A team of scientists and medieval historians, led by the University of Cambridge, has used information contained within ice cores and tree rings to accurately date a massive volcanic eruption, which took place soon after the island was first settled.

Having dated the eruption, the researchers found that Iceland’s most celebrated medieval poem, which describes the end of the pagan gods and the coming of a new, singular god, describes the eruption and uses memories of it to stimulate the Christianisation of Iceland. The results are reported in the journal Climatic Change.

The eruption of the Eldgjá in the tenth century is known as a lava flood: a rare type of prolonged volcanic eruption in which huge flows of lava engulf the landscape, accompanied by a haze of sulphurous gases. Iceland specialises in this type of eruption — the last example occurred in 2015, and it affected air quality 1400 kilometres away in Ireland.

The Eldgjá lava flood affected southern Iceland within a century of the island’s settlement by Vikings and Celts around 874, but until now the date of the eruption has been uncertain, hindering investigation of its likely impacts. It was a colossal event with around 20 cubic kilometres of lava erupted — enough to cover all of England up to the ankles.

The Cambridge-led team pinpointed the date of the eruption using ice core records from Greenland that preserve the volcanic fallout from Eldgjá. Using the clues contained within the ice cores, the researchers found that the eruption began around the spring of 939 and continued at least through the autumn of 940.

“This places the eruption squarely within the experience of the first two or three generations of Iceland’s settlers”, said first author Dr Clive Oppenheimer of Cambridge’s Department of Geography. “Some of the first wave of migrants to Iceland, brought over as children, may well have witnessed the eruption.”

Once they had a date for the Eldgjá eruption, the team then investigated its consequences. First, a haze of sulphurous dust spread across Europe, recorded as sightings of an exceptionally blood-red and weakened sun in Irish, German and Italian chronicles from the same period.

Then the climate cooled as the dust layer reduced the amount of sunlight reaching the surface, which is evident from tree rings from across the Northern Hemisphere. The evidence contained in the tree rings suggests the eruption triggered one of the coolest summers of the last 1500 years. “In 940, summer cooling was most pronounced in Central Europe, Scandinavia, the Canadian Rockies, Alaska and Central Asia, with summer average temperatures 2°C lower”, said co-author Professor Markus Stoffel from the University of Geneva’s Department of Earth Sciences.

The team then looked at medieval chronicles to see how the cooling climate impacted society. “It was a massive eruption, but we were still amazed just how abundant the historical evidence is for the eruption’s consequences”, said co-author Dr Tim Newfield, from Georgetown University’s Departments of History and Biology. “Human suffering in the wake of Eldgjá was widespread. From northern Europe to northern China, people experienced long, hard winters and severe spring-summer drought. Locust infestations and livestock mortalities occurred. Famine did not set in everywhere, but in the early 940s we read of starvation and vast mortality in parts of Germany, Iraq and China.”

“The effects of the Eldgjá eruption must have been devastating for the young colony on Iceland — very likely, land was abandoned and famine severe”, said co-author Professor Andy Orchard from the University of Oxford’s Faculty of English. “However, there are no surviving texts from Iceland itself during this time that provide us with direct accounts of the eruption.”

But Iceland’s most celebrated medieval poem, Voluspá (‘The prophecy of the seeress’) does appear to give an impression of what the eruption was like. The poem, which can be dated as far back as 961, foretells the end of Iceland’s pagan gods and the coming of a new, singular god: in other words, the conversion of Iceland to Christianity, which was formalised around the turn of the eleventh century.

Part of the poem describes a terrible eruption with fiery explosions lighting up the sky, and the Sun obscured by thick clouds of ash and steam:

“The sun starts to turn black, land sinks into sea; the bright stars scatter from the sky. Steam spurts up with what nourishes life, flame flies high against heaven itself.”

The poem also depicts cold summers that would be expected after a massive eruption, and the researchers link these descriptions to the spectacle and impacts of the Eldgjá eruption, the largest in Iceland since its settlement.

The poem’s apocalyptic imagery marks the fiery end to the world of the old gods. The researchers suggest that these lines in the poem may have been intended to rekindle harrowing memories of the eruption to stimulate the massive religious and cultural shift taking place in Iceland in the last decades of the tenth century.

“With a firm date for the eruption, many entries in medieval chronicles snap into place as likely consequences — sightings in Europe of an extraordinary atmospheric haze; severe winters; and cold summers, poor harvests; and food shortages”, said Oppenheimer. “But most striking is the almost eyewitness style in which the eruption is depicted in Voluspá. The poem’s interpretation as a prophecy of the end of the pagan gods and their replacement by the one, singular god, suggests that memories of this terrible volcanic eruption were purposefully provoked to stimulate the Christianisation of Iceland.”

Etna volcano erupts in Italy


This 28 February 2017 video says about itself:

Etna: the volcano in Italy

The current stratovolcano located on the Eastern coast of Sicily, near the cities of Messina and Catania. It is the highest point of Europe outside of the Caucasus mountains, the Alps and the Pyrenees, and the highest active volcano in Europe. Now the height of mount Etna is 3329 m above sea level. It often varies from eruption to eruption. So, now the volcano is 21.6 m lower than it was in 1865.

Big volcano eruption in Hawaii


This video from Hawaii says about itself:

31 January 2017

Kilauea Volcano lava stream at the Kamokuna ocean entry between 25 – 29 January 2017. According to USGS, “Kīlauea Volcano continues to erupt at its summit and East Rift Zone. Lava continues to enter the ocean at Kamokuna and surface flows remain active within 2.4 km (1.5 mi) of the vent at Puʻu ʻŌʻō.”

New Zealand ‘Lord of the Rings’ volcano eruption?


This video from New Zealand is called Mt Ruapehu Crater Climb (February, 2016).

Mount Ruapehu is well-known because much of the movie The Lord of the Rings was filmed there; scenes depicting Mordor and Mount Doom.

From the New Zealand Herald:

Ruapehu on alert after 20C rise

Wednesday, 11 May 2016

By Chris Schulz

Mt Ruapehu’s risk of eruption may have increased, but GNS volcanologists say nearby residents should not feel concerned.

GNS today announced the mountain’s crater lake temperature had doubled in the past few weeks, rising from 25C to between 45C and 46C over the past couple of days.

Duty volcanologist Geoff Kilgour says scientists made two visits to Ruapehu yesterday, one flight to measure the gas output and other to sample the crater lake water and make additional ground-based gas measurements.

Volcanic gas measurements indicate an increase in the amount of both carbon dioxide (CO2) and sulphur dioxide (SO2) output … Seismic activity at Mt Ruapehu is usually dominated by volcanic tremor. Since the volcanic earthquakes in late April the seismicity has been dominated by volcanic tremor at varying levels. The level of tremor has increased but is not exceptional in terms of the last few years.”

Volcanologist Brad Scott has quashed a few “urban myths” about why there is currently an increasing level of activity in the volcano.

“It’s got nothing to do with weather. And White Island, they’re [volcanoes] all independent of each other.”

Mr Scott says the activity is caused by molten lava getting trapped inside the volcano itself.

“When that new pulsar heat and hot rock comes into the volcano it’s whether or not it can flow through the volcano and get out of it and if the holes in the volcano aren’t big enough to let the gas through it just over pressurises and pops.”

And for those in surrounding towns worried that a lahar will swamp them, Mr Scott says debris is unlikely to travel more than a few kilometres from the volcano itself.

“One of the biggest eruptions, in 1995, only a few blots got past the 3km or 4km mark and that was really rare. Being away from the volcano is very safe and even the standard places you can go. Different story if you go and climb the thing and you’re camping at the crater lake or something.”

As for where it travels, Mr Scott says the majority head out towards the Desert Rd but there have been some eruptions producing lahar on the northern side.

“If you’re at the ski lodges, they’re safe as. Ruapehu only affects within about 3km of the lake and the nearest part of the ski fields are about 4km or 5km away so it does make it a fairly safe environment and the rest, once off you’re off the bottom of the volcano, nothing can touch you.”

Mr Scott says Ruapehu Alpine Lifts has shifted all of its infrastructure – ski tows, towers, cafes – out of the valleys in case it did head in that direction.

As for how the volcanic unrest occurs? “That’s the $64,000 science question of volcanologists all over the world.”

The Department of Conservation also issued a warning to climbers and trampers on the mountain, to not enter the Summit Hazard Zone on Mt Ruapehu until further notice.

The Summit Hazard Zone is the area within 2km of the centre of the crater lake.

It encompasses all the peaks in the summit area, with Te Heuheu Peak at the north end of the summit area at the edge of the zone, and the upper Turoa skifield at the south.

Climbers and trekkers should refer to the Summit Hazard Zone map or use their map and GPS reading skills, to determine when they are approaching the zone.

“We recommend climbers, trampers and walkers do not enter the zone,” said Paul Carr, DoC‘s operations manager for Tongariro.

“Guiding companies should also heed the advice and not take people into the zone.”

No ski areas, other facilities or roads on Ruapehu or elsewhere in Tongariro National Park – including the Tongariro Alpine Crossing – are affected by this warning.

USA: Mount St. Helens is a cold-hearted volcano. Scientists are still searching for the source of volcano’s heat. By Beth Geiger, 12:00pm, November 1, 2016: here.

Volcano erupts on sub-Antarctic Heard island


This video says about itself:

Rare video of Heard Island volcano Big Ben erupting

31 January 2016

Scientists on board the CSIRO research vessel Investigator have taken rare video footage of an eruption of the Big Ben volcano on remote sub-Antarctic Heard Island during an IMAS voyage to the Kerguelen Plateau.

Big Ben, which includes the 2,745 m tall Mawson Peak, the highest mountain on Australian territory north of Antarctica, is known to have erupted at least three other times since 2000.

But the remoteness of Heard Island and the neighbouring McDonald Islands, also an active volcano, means eruptions are rarely glimpsed by people and usually only recognised from sparse satellite images.

RV Investigator is circling the islands on the sub-Antarctic Kerguelen Plateau as part of an IMAS-led voyage to study the link between active volcanoes on the seafloor and the mobilisation of iron which enriches and supports life in the Southern Ocean.

Voyage Chief Scientist, IMAS’s Professor Mike Coffin, and PhD candidate Jodi Fox comment on the eruption.