The harbour of Heimaey, along the south coast of Iceland is a small town named Vestmannaeyjar with a population of 5400 people. Vestmannaeyjar provides some the of the best fishing areas in the North Atlantic. A loss of this fishing harbour would see a fall in Iceland’s economy (Bullard, 1977). Until mid-January in 1973 the island of Heimaey was considered to be volcanically inactive. The last known eruption of Helgafell was inferred to be 5000 – 6000 years ago. (Bullard, 1977) there was no real warning of Helgafell erupting other than two swarms of earthquakes which began on 21 January 1973 and on 22 January a gale of wind which has raged and left 70 ships in the harbour seeking shelter. The Eruption started in the early morning of 23 January 1973 from a 1600 meter long fissure. The fissure was located 200 meters to the East of the town. The lava flowed away from the town due to favourable morphological conditions. Due to favourable conditions such as the wind blowing west, pyroclastics ejected from the fissure were redirected away from the town. These conditions contributed to the safety of the residents as they were evacuated from the town to safer locations via the stranded ships. (Kolbl, 29 June 1996)
A new edifice began to grow where the eruptive activity were focused at a section of the fissure where fountaining became more energetic. Due to the prevailing winds returning to their seasonal directions and the nearest houses of the town located a short distance away
To what extent can preparedness and planning mitigate the effects of a volcanic hazard (40 marks)
The volcano had been dormant for hundreds of years and this violent explosion lasted days, sending ash into the atmosphere (D'arcy Wood). At the time, there were both native villagers living in the area and British officers, as the area was a colony under the British crown. Most of the surviving records of the explosion come from these British officers, some of whom didn’t actually witness the explosion but heard it and assumed the explosion was from rebels on the island. A captain of a nearby East India Company ship reported ash falling out of the sky and “By noon, the light that had remained in the eastern part of the horizon disappeared, and complete darkness had covered the face of day” (D'arcy Wood). At the time of the explosion another British subject, Sir Thomas Raffles, was the governor of Java, Indonesia. His compiled record of first hand accounts confirming the blackened sky and falling ash (Skulls). Similar accounts of darkness were recorded throughout the region, which was due to the sheer volume of ash that was released by the volcano. The ash-blackened sky was not the only impact of the eruption. The more far reaching effects of the eruption would not be felt until the summer of 1816, when the eruption gasses and particles so affected worldwide meteorological patterns that the western world called 1816 “The Year Without a Summer”.
With no prolonged periods of inactivity the volcano has continuously built up on itself. The last major eruption took place in 1790 and killed many people and animals, but numbers are unknown4. Starting in 1983 there was a chain of several eruptions that started and have yet to stop pushing lava through a lava tube till it reaches the Pacific Ocean. Over a span of twenty year the flow has
Assess the extent to which primary rather than secondary impacts are the more serious effects arising from volcanic eruptions. (30 marks)
A hazard is a situation that poses a level of threat tolife, health, property or environment. The level of hazard posed by different volcanoes can very greatly, from a weak eruption with minimal impact that causes little damage, to a voilent and life threatening explosion. Most of the sixty-plus volcanoes that erupt each year are low risk, however a combination of factors can cause a volcano to be a serious hazard. The factors causing these variations will be explained in this essay.
Water vapor given off from hot lava coming into contact with the sea causing it to evaporate
Volcanoes are one of the most destructive, yet, most beautiful things on Earth. They can make a famous city choke in its own ashes in one day, like Pompeii. Or they can turn a once damaging mountain into a graceful and peaceful home for new life, like Mount St. Helen’s. All volcanoes are unique, and no two are the same. Some erupt differently than others, some look different than others, and all are located in different spots all over the world. I learned this while completing the project and the five volcanoes I researched are examples of my discoveries. The five volcanoes I researched were Mount Hood, Mount Mageik, Long Island, Mount Muria, and Las Pilas.
In the early 1900s St.Pierre on the French Caribbean island of Martinique was famous tourist destination.”It was known as the Paris of the west Indies”, and home to more than 20,000 people,Mount Pelee sits about 4 miles from St Pierre.On May 8, 1902 the volcano erupted. Sending a volcanic surge directly at St.pierre's at a rate of 420 miles per hour.Killing 30,000 people in its wake.National National Geographic News”Deadliest volcano of the 20th century, 100 years later””molly pell and channo wOodage for National Geographic News, 5-8-2”
Another physical factor is snow; if a volcano is snow capped, like Eyjafjallajokull, then the lahars and flash floods become a greater hazard. The flooding in Iceland in 2010 caused 700 people to be evacuated. Without the snow then lahars and floods may not be a problem at all.
A human factor that would cause differences in the hazards posed by volcanoes is settlement, which includes where people chose to live in relation to a volcano. For example, in Indonesia many people settle near Mount Merapi because of the rich and fertile soil favoured for farming. As Indonesia is a poor country many people rely on subsistence farming, therefore are willing to risk everything by settling beside a volcano. Furthermore, in the last eruption in 2010 360,000 people were displaced from their homes, meaning not only did they lose their home but also their livelihood; hundreds also lost their lives. Therefore, the hazards posed could have been minimalised if people chose to settle elsewhere.
Another well-known geological phenomenon in the United States is Yellowstone Park. Yellowstone is an extraordinary example of a caldera which is defined as “a volcanic crater that has a diameter many times that of the vent and is formed by collapse of the central part of a volcano or by explosions of extraordinary violence”(USGS). Since Yellowstone is a caldera, it means that there had been previous volcanic eruptions in this area and in this case two eruptions. The first explosion happened over 2,000,000 years ago because the composition of the magma contained vast traces of explosive matter that caused the eruption (USGS). The second incident happened around
The blast was preceded by two months of intense activity that included over 10,000 earthquakes, hundreds of small phreatic (steam blasts) , explosions and the north side bulge. A magnitude 5.1 earthquake below the volcano at 8:32 am started the eruption. MSH is still a potentially dangerous and active volcano even though it has been quiet since 1995. In the last 515 years there have been four major eruptions and dozens of lesser eruptions. Two of the eruptions were only two years apart. In 1480, the eruption was about five times larger than the one in May 1980. There have been even larger eruptions during MSH' 50,000 year lifetime. After the May 18, 1980 eruption, there have been five smaller explosive eruptions over a five month period. Since then, there have been 16 dome building eruptions through October 1986 when the new dome in the crater was formed. As the mountain was torn open, the pressure in inside was suddenly relieved. The rock shattered inside the mountain was exploded out the top at speeds over 200 miles per hour. The blast was so strong that it leveled whole forest of fir trees. Geologist call this a "stone wind" since the winds carried the rocks form the blast with them. The rocks gave the winds extra force that let them flatten the trees. 150 square miles of land was leveled. The edges of this area also lost their forested areas from the heat of the blast and the fires it caused. The original blast of the
The first cautionary signs start at 6:12pm yesterday evening. At time when a tower of black smoke was speckled over the volcano. Suddenly, a wave of remains of burning ash, rocks and gasses start to fall down over the North
Mount Vesuvius is one of history’s most recognizable Volcanoes, as each of its eruptions have gone down as a significant event in geologic history. The events that transpired during and after these eruptions have shaped the way scientists and people view the sheer power that these volcanoes possessed. This report will take a look at Vesuvius’ most prolific eruption in 79 AD. The geologic setting of the mountain, precursor activity, and the impact the eruption had on the surrounding populations and towns will all be detailed. Along with these details, this report will also look at the further history of Vesuvius’s explosive past by detailing its eruption cycle. Finally, the current state of Vesuvius and the possible danger
The country that I choose is Iceland. Iceland is very unique and interesting not only because of its clean air and amazing scenery but also its natural beauty and landscapes. Nature is a big force of Iceland but the volcano’s, waterfalls, and glaciers seem to attract most tourist. There landforms are probably the most unique. The Northern Lights is also something that people find very interesting because how it is created and the view you can see. It is something that everyone should see at some point in their life. The sources that I choose to use to research the Physical Geography, Economics, History, Cultural, and Political