13.3 GROUP 2 To what extent is the impact of a volcanic eruption related to the type of eruption? (33 marks) by Miss Stewart

Paragraph 4 - Disagree (1) - Henry Collins

2023-11-17 10:13:44 UTC

On the other hand, the extent to which the impact of a volcanic eruption is then related to the type of eruption is limited, due to other more significant factors such as the development level of affected areas. For example, in 1902 people living in the vicinity of Mount Pelee in Martinique were extremely unprepared for the Plinian eruption that occurred. Due to the development level of the Island, there were no early warning systems or sufficient resources to help residents prepare encase of an eruption. This led to the devastating pyroclastic flow to destroy the local areas and led to the deaths of around 29,000 people, with only two survivors in the affected areas on a whole. Conversely, in 1980 many lives were saved around Mount St. Helens as a result of increased communications and resources in the more developed country of the US. Residents (roughly 20,000) who lived in the direct danger zone around the volcano were given evacuation orders before the eruption and had resources to manage this. This advanced warning driven by the very high development level of the US led to a much smaller death toll of around 60 people. Despite both having lethal pyroclastic flows that travelled in excess of 100mph, the evacuation orders and prepared state of those near St. Helens made the impact of the volcano significantly lower as they could evacuate the exact danger zone. If those in Martinique could have had the same warnings and management through a higher level of development, it can certainly be assumed that the death toll could have been reduced significantly. This shows directly how the impact of a volcano is not always related to the type of eruption. A state of preparation driven by increased resources in more developed countries can have a significantly lower impact in terms of death tolls comparatively to those who do not access this due to lower levels of development, even when originating from the same type of eruption and with the associated risks.

WWW: Very good AO2, as development levels are talked about throughout, and the levels of development of the USA and Martinique are compared throughout.

EBI: Maybe look at impacts of the eruptions on multiple scales, as mainly local scale looked at.

Paragraph 2 - Agree (2) - Remi

2023-11-19 13:37:10 UTC

One reason the type of eruption is the most significant factor towards the impact of a volcanic eruption is due to how Plinian eruptions produce the most devastating impacts of any type of eruption. Composite volcanoes produce Plinian eruptions, they are made up of layers of ash & acid lava and can be found above subduction zones at convergent plate boundaries. The highly viscous magma found in the vents of a composite volcano does not flow smoothly, this leads to the vents becoming blocked with effectively solidified magma. This causes enormous pressure to build up as magma trying to emerge from deep within the Earth is unable to move freely. Eventually this causes an extremely explosive eruption capable of producing deadly pyroclastic flows and Lahars. An example of when a Plinian eruption occurred is when Mount St. Helens erupted in 1980 and created thick pyroclastic flows and ash fall. As a result 57 people were killed, over 10 million trees were destroyed and marine life in the surrounding 25 km blast zone was likely killed due to ash entering the lakes / rivers. Therefore the immense impact of a Plinian eruption demonstrates how the type of eruption is massively linked to the type of eruption that takes place.

WWW: Thorough knowledge of how a Pilnian eruption happens

EBI: Spend less time describing why the eruption happens and focus on answering the question through the impacts on different scales compared to another eruption, or assess wether a more developed country would have had a lesser impact upon their country if faced with the same explosion

Paragraph 5 - Disagree (2) - Freya marked by Jake

2023-11-19 14:28:37 UTC

However, the extent at which impacts of volcanic eruptions relates to the kind of eruption can be limited due to other extenuating circumstances. For example, the geographical location of the volcano will effect and vary the scale of the impacts. An example of this is the Eyjafjnallajokull (E15) Icelandic eruption in 2010. The local environment around the Eyjafjnallajokull eruption was a sub zero climate, meaning a glaciated and cold landscape. this resulted a phreatomagmatic eruption, resulting in lots of ash production, reaching up to 10km high. Although the explosion was effusive and not highly explosive, due to the ice cap, the explosion scale was amplified hugely. This is caused by both the magma and water, which typically interact explosively but due to immediate solidification, this lead to concurrent ejection of steam and pyroclastic fragments. This resulted in many global issues, for example; airlines such as British airways taking routes across Europe and the trans Atlantic were heavily effected due to unsafe travel, caused by the material produced from the eruption, being at a 4 of the VEI. The local environment of the eruption is shown the have a very significant role within the effects of a volcanic eruption, showing it not to always be defined by the type of eruptions itself. As, shown by the Eyjafjnallajokull eruption, the presence of the icecap amplified the effects of the eruption, which without the icecap, would ahem been a much smaller scale effusive eruption.

WWW: lots of AO1 and AO2 and is clear what you are arguing for.

EBI: more selective with AO1

Paragraph 3 - Agree (3) - Duncan

2023-11-19 18:24:44 UTC

Marked by Finn

In some ways, the impact of a volcanic eruption is related to the type of eruption, because certain types cause greater damage to crops than others. For example, the eruption of Mount Tambora, Indonesia in 1816 caused catastrophic damage to global food supplies because it was a Pilinian eruption. The magma involved was acidic and high in silica, causing it to be very viscous, which blocked the volcano's vents and trapped gases, causing enormous pressures to build up. Eventually Mount Tambora erupted in an incredibly explosive eruption ejecting ash and gas such as sulphur dioxide into the atmosphere as a 45 km tall column. The sulphur dioxide was converted to sulphuric acid in the atmosphere, and formed a sulphate aerosol cloud the size of Australia, blocking insolation in the troposphere from reaching Earth. This caused global temperatures to fall by 1 degree Celsius, which led to a global failure in crop production, causing famine, showing that this very explosive Pilinian eruption caused significant crop damage. However, Kilauea in Hawaii, the most active volcano in the world, typically experiences effusive, Hawaiian eruptions with magma low in silica. Its low silica content makes the magma not very viscous, so less pressure builds up inside the volcano's vents, causing more gentle eruptions. When they occur, the lava tends to remain within the main crater in the Halema'uma'u lava lake, occasionally rising over the sides of the caldera. As the eruptions are often very self-contained, little material comes into contact with farmland, causing minimal, if any, damage to crops, showing that these Hawaiian eruptions have little agricultural impact, in sharp contrast to the effects of Mount Tambora. In this way, it is clear that a volcanic eruption's damage to crops is very dependent on factors such as explosivity, lava type and volume of gases emitted. Therefore, the impact of an eruption is very closely related to the type of eruption.

WWW:

good comparison between the different types of eruptions.
good links to global food security

EBI:

link more of your AO1 in so that it is more useful

Paragraph 1 - Agree (1) - Ben

2023-11-20 01:44:32 UTC

The type of eruption has a significant effect on the impacts that follow an eruption such as global politics. The 2010 Eyjafjallajokull eruption saw a phreatomagmatic eruption where the volcano erupted underneath an ice cap. Such an eruption occurs when magma comes into contact with the ice, solidifies and then shatters into fine ash which is blown by the wind and can build up on turbofan engines and reduce the thrust produced which makes flying in fine ash dangerous. This resulted in cancellations of air routes throughout the affected areas which affected many thousands of travelers and presented an issue for world leaders officially traveling abroad. Jens Stoltenburg, Norwegian PM had to run from New York while the US President Barack Obama was forced to cancel his attendance at a state funeral in Poland and German Chancellor Angela Merkel could not return to Germany from Rome by air. The political impact of the volcanic eruption was therefore felt around the world where the ash was deemed flying unsafe and resulted in cancellations of official events and the inability of face to face interactions which are important for politicians. Had Eyjafjallajokull not experienced a phreatomagmatic, the global political and economic impacts of the eruption would have been significantly lessened where the ash would have been minimal. Therefore the type of eruption has a profound effect on the impact because of the disruption caused by ash which happens as a result of certain types of eruption.

AO1

AO2

WWW: lots of detailed information on the consequences of the volcano and how it’s impacts were very specific.

EBI: Use more AO2 links and maybe discuss more specific economic impacts rather than just saying they were impacted.

Introduction

2023-11-20 07:48:53 UTC

Volcanic eruptions create a range of hazards, such as ash clouds, lava flows and pyroclastic flows, which have environmental, economic and political impacts on a local to global scale. These impacts are very dependent on the type of eruption, for example, whether it is explosive or effusive, because this heavily influences which hazards are produced. However, the impacts of an eruption are also affected by factors such as the level of economic development of a region or geographical location of the eruption. However, overall, the impacts of an eruption are very closely related to the type of eruption because this is the most significant determinant of the hazards which are created.

Conclusion

2023-11-20 07:50:37 UTC

In conclusion, the impacts of an eruption are very closely related to the type of eruption. The level of economic development can heavily influence the effectiveness of early warning systems and thus determine the damage caused to infrastructure and loss of life, and the geographical location can also partly influence the hazards produced by an eruption and the spatial scale of its impacts, but the type of eruption has the greatest influence on what types of hazards are produced and the intensity of these hazards, which in turn affect the level of damage caused, irrespective of other factors. Therefore, overall, the impacts of an eruption are very closely related to the type of eruption.