A volcano is an opening, or rupture, in a planet’s surface or crust, which allows hot magma, volcanic ash and gases to escape from below the surface. Erupting volcanoes can pose many hazards, not only in the immediate vicinity of the eruption.
Volcanic ash can be a threat to aircraft, in particular those with jet engines where ash particles can be melted by the high operating temperature.
Almost surreal, volcanic eruptions viewed from the Earth’s orbit often appear like little more than patterns of white and grey smoke that nature creates to change existing landscapes and make them a bit more interesting for us. Only those unfortunate earthlings on the ground and near to the action know that nothing could be further from the truth.
During a volcanic eruption, lava, tephra (ash, lapilli, volcanic bombs and blocks), and various gases are expelled from a volcanic vent or fissure. Several types of volcanic eruptions have been distinguished by volcanologists. Some volcanoes may exhibit only one characteristic type of eruption during a period of activity, while others may display an entire sequence of types all in one eruptive series.
Volcanic eruptions arise through three main mechanisms:
• Gas release under decompression causing magmatic eruptions.
• Thermal contraction from chilling on contact with water causing phreatomagmatic eruptions.
• Ejection of entrained particles during steam eruptions causing phreatic eruptions.
There are two types of eruptions in terms of activity, explosive eruptions and effusive eruptions. Explosive eruptions are characterized by gas-driven explosions that propels magma and tephra. Effusive eruptions, meanwhile, are characterized by the outpouring of lava without significant explosive eruption
Today in this post I have describe a 10 most unbelievable Volcanic Eruptions Seen from earth…
1. Puyehue-Cordón Caulle, Chile, 2011
The volcanic group that is the Puyehue-Cordón Caulle Volcanic Complex (PCCVC) is actually made up of four different volcanoes. Between June 2 and June 3, 2011, increased activity was detected, as close to 1,500 earthquakes shook the Earth, heralding the start of the eruption.
We can see the massive ash and gas plume that billowed into the air. Thousands of people were evacuated, long before lava even began to spill from the volcano 18 days after it first erupted.Here’s a close-up of the thick plume of volcanic ash that traveled 6.2 miles (10 km) up into the air and drifted around the globe after the Puyehue-Cordón Caulle eruption, causing airports as far away as Buenos Aires and Melbourne to close.
More devastating, however, were the consequences for the surrounding environment: the temperature of the nearby Nilahue River rose to 45 °C (113 °F), killing about 4.5 million fish; and, after five years of drought suffered by two provinces in Argentina, the remaining usable farmland was destroyed, endangering 750,000 sheep and 60,000 cattle.
2. Eyjafjallajökull, Iceland, 2010
Many people remember the eruption of the Icelandic volcano with the unpronounceable name that affected the schedules of so many flights – and the travel plans of hundreds of thousands of travelers – in northwestern Europe in 2010. Here we can see the large ash plume spreading out over the North Atlantic on April 17, a plume that rose 5.6 miles (9 km) into the air.
On May 13, 2010, the area surrounding Eyjafjallajökull appeared to be covered by a blanket of smoke, ash and clouds, as this dramatic image shows. It’s hard to believe that a week-and-a-half later, the situation – which caused the highest level of disruption to air travel since World War Two – had calmed down considerably. By May 24, Eyjafjallajökull was emitting only steam and sulfurous gases and appeared to be dormant. At least for the time being.
3. Soufrière Hills, Montserrat, 2009/2004
This image shows the Soufrière Hills (French for Sulfur Hills) stratovolcano venting a plume of ash and steam in October 2009. The grey deposits extending from the volcano toward the Caribbean Sea surrounding Montserrat are pyroclastic flows and lahars (volcanic mud flows), slowly taking over the vegetation-covered parts of the island.
After a long dormant period, Soufrière Hills became active in 1995 and has been erupting more or less non-stop ever since. Small wonder that it is one of the most closely monitored volcanoes on the planet – especially given the fact that Montserrat’s capital city Plymouth has been totally destroyed by the volcano’s eruptions and around two thirds of the island’s inhabitants have fled. In this image, from 2004, an ash plume can be seen emanating from the volcano.
4. Mount Merapi, Indonesia, 2010/2003
The 2010 eruptions of Java’s Mount Merapi did not turn the Earth scarlet as this dramatic image might suggest; rather, we’re rather looking at a false-color satellite image. Light gray areas show volcanic deposits such as pyroclastic flows and lahars (volcanic mud flows) and the dark gray areas almost total devastation, while the healthy vegetation is colored red.
“Within this dark gray area, most of the trees were knocked down and the ground was coated by ash and rock,” reads a description by NASA.
The eruptions of Mount Merapi began in late October 2010 and became increasingly violent over the ensuing month. As lava and ash spewed forth from the volcano, hundreds of thousands were evacuated from the affected area, but some remained behind and 353 lost their lives – mainly due to pyroclastic flows.
The plume of volcanic debris also disrupted air traffic over Indonesia. August 2003, we can see a plume of emanating from Merapi’s crater. As of November 30, 2010, Mount Merapi stopped erupting but is still closely watched, as seismic activity could set it off again.
5. Chaitén, Chile, 2008
Pictured here is the massive plume of ash and sulfurous steam – which rose to a height of 19 miles (31 km) – seen after the eruption of Chile’s Chaitén volcano, beginning on May 2, 2008. Before that date, the volcano had lain dormant for more than 9,000 years. Luckily, the town of Chaitén was quickly evacuated – because it was completely flooded on May 12 after lahars caused the Blanco River to overflow.
Due to the damage, the town had to be abandoned, with plans since made to rebuild it in one of two different locations.
Chaitén volcano shows the bare, rocky surface of the new lava dome, with the land to the east covered by ash and volcanic debris, and dead and dying vegetation littering nearby slopes following two years of volcanic blasts and ash-fall. Notice the untouched, green vegetation on the western side, which the prevailing winds kept out of reach.
6. Mount Redoubt, Alaska, 2009
Mount Redoubt, in Alaska’s Aleutian Range, showed weeks of unrest in early 2009 before erupting violently on March 22 – five times in one night. In this image, we can see a steam plume over a mile in diameter that was captured in May 2009.
This image shows the plume of ash, volcanic ash and steam released by Mount Redoubt on April 1, 2009, stretching far across and beyond the Cook Inlet. The emissions were occasionally thrown up as high as 25,000 feet (7,620 m).
7. Nabro Volcano, Eritrea, 2011
The eruption of the Nabro stratovolcano in Eritrea’s Red Sea region began on June 12, 2011, following a succession of earthquakes. It interrupted air traffic and released the highest quantities of sulfur dioxide into the atmosphere ever observed from the Earth’s orbit.
The inhabitants of three towns had to be evacuated and as many as 38 people lost their lives. The dark ash plume billowing out from the vent is clearly visible in this image, but it is the gas plume of steam and sulfur dioxide (the latter lending the cloud a blue tinge) that dominates, obscuring the lava flow beneath.
This false-color image shows the full scale of the Nabro eruption on June 19, 2011, with the lava flow in white. Interestingly, before the eruption, the volcano was believed to be extinct – which just goes to show that one never knows what’s brewing in the depths of the Earth.
8. Mount Nyiragongo, Democratic Republic of the Congo, 2002
Increased seismic and fumarole activity triggered the eruption of Mount Nyiragongo, in the Virunga Mountains, on January 17, 2002. A large lava flow up to 3,280 feet (1000 m) wide and 6.5 feet (2 m) deep swept through Goma, destroying significant parts of the city, causing 400,000 to be evacuated, and leaving 120,000 homeless. A further 47 people were also killed.
9. Shiveluch, Russia, 2007/2004
In this image, taken on September 7, 2010, we can see a large ash plume stretching out from the volcano, as well as volcanic debris in brown and tan covering the volcano’s southern reaches (snow and ice remain on the northern side).
The ancient stratovolcano is, says NASA, “composed of alternating layers of solidified ash, hardened lava, and volcanic rocks” and has been erupting on and off since August 15, 1999. The nearest town is 28 miles (45 km) away and is small enough to be easily evacuated in the event of a major eruption.
10. Mount Etna, Italy, 2002
The spectacular image at the beginning of the post shows the eruption of Mount Etna on October 30, 2002. At the time, a three-member crew on board the International Space Station was able to capture the details of the spectacular eruption. This shows just how far the ash cloud was curving out towards the southeast and over the whole of Sicily.
The lighter-colored plumes in the picture here are not multiple eruptions but forest fires caused by the hot lava flowing into the trees that line the slope of the mountain. The 2002 eruption followed six years of unusually intense activity – from 1995 to 2001 – and while Etna has experienced considerably bigger eruptions, ash still fell as far away as Libya, 370 miles (600 km) away.
As fascinating as volcanic eruptions may be from space, they remind us of how inconsequential we humans become when the forces of nature are at play.