Comparing Tectonic Settings and Risk: Volcanic Eruptions

This assignment compares two major volcanic eruptions: a shield volcano (Galapagos Island) and a stratovolcano (Unzen Volcano). It begins with an introduction to volcanoes, defining them as ruptures in the Earth's crust caused by tectonic plate movement. The assignment describes the characteristics of each volcano type, including their formation and geographical locations. It then details the tectonic settings for each eruption, referencing the Nazca and Cocos plates for the Galapagos Island and the Pacific and Philippine plates for Mount Unzen. A comparison of eruption styles, hazards (such as toxic gases, ash, and lava), and risk factors is provided, highlighting the differences in the impact of each type of volcano. Finally, the assignment discusses measures for volcano risk preparedness, emphasizing the importance of emergency alerts, safe evacuation plans, and support for individuals with respiratory issues. The conclusion reiterates the significant environmental impact of volcanic eruptions and the need for identifying risk factors to develop effective safety measures.

Running head: GEOGRAPHY
Geography
Name of the Student:
Name of the University:
Author note:

1GEOGRAPHY
Table of Contents
Introduction................................................................................................................................2
Discussion..................................................................................................................................2
Shield volcano: Galapagos Island..............................................................................................2
Stratovolcano: Unzen Volcano..................................................................................................2
Description of the tectonic setting..............................................................................................3
Comparison................................................................................................................................4
Comparison of the risk factors...................................................................................................4
Measures to be taken..................................................................................................................4
Conclusion..................................................................................................................................5
Reference List............................................................................................................................6

2GEOGRAPHY
Introduction
The rapture of the crust of the planetary-mass object is known as volcano. The
volcano that occurs is due to the movement of the tectonic plates that floats on the hot and
soft molten layer in the mantle. According to Sato, Holtz, Botcharnikov & Nakada (2017),
the sudden eruption of molten lava from the earth that has a great impact on the nature as well
as in the people who are living nearby. The paper will help to understand different types of
volcano and the impact on the environment.
Discussion
Shield volcano: Galapagos Island
The shield volcano is a type of volcano that is mostly made of lava. The lava is the motel fire
that travels a long distance from the area of eruption. It resembles like a worrier’s shield lying
on the ground (Malavelle et al., 2017). The Galapagos Island is one of the famous volcano
that is isolated set of volcanoes and lava plateaus, which is located, 1200 km west to Ecuador.
It is around 4.2 million to 700,000 years old. It is being distributed in both the side equator of
the Pacific Ocean that is being surrounded by the center of the Western Hemisphere. The
volcanic eruption in the Galapagos Island has been since a long time, which can be more than
20 million years.
Stratovolcano: Unzen Volcano
The stratovolcano is also known as the composite volcano, which is made up of
various kind of materials like lava, tephra, ash and pumice (Sato, Holtz, Botcharnikov &
Nakada, 2017). The Unzen Volcano is a series of active volcanic group with various
overlapping stratovolcano. Chitose Caldera is the place where it is located that is being
centred by the Tachibana Bay in the western peninsula. It consists of total 20 mountains.

3GEOGRAPHY
Description of the tectonic setting
Every volcano is caused due to the sudden movement of the plates. The Galapagos
Island volcano is caused due to the Nazca and Cocos plates that has a triple junction with the
pacific plates. As mentioned by Ashworth et al. (2017), the Mount Unzen is being established
in the Pacific and Philippine plates that are subducting under the Eurasian plate.
Fig 1: Shield volcano (Galapagos Island)
(Source: Malavelle et al., 2017)
Fig 2: Stratovolcano (Unzen Volcano)
(Source: Schlenker et al, 2017)

4GEOGRAPHY
Comparison
The stratovolcano is a type of volcano that is being formed with various kinds of
material whereas the shield volcano is made up of lava only (Tejedor et al., 2018). The
eruption in the shield volcano is not as impactful or violent like the stratovolcano. In
stratovolcano, eruptions can take place in any time, whereas in shield volcanoes the eruptions
are passive. The stratovolcano has various layer of composites whereas the shield volcano has
only the molten lava.
Comparison of the risk factors
A large amount of toxic gases and hazards that has been formed due to volcanoes that
has been making it difficult for people to live in areas near volcanic eruptions (Johnson,
2017). There is a massive amount of ashes and gases released from the stratovolcano.
Whereas in the shield volcano there is release of hot molten lava. The stratovolcano is a
dangerous volcano that can erupt in any time whereas the shield volcano is a volcano wherein
the molten lava flows slowly and steadily that can help in making people aware of the
situation and save various lives.
Measures to be taken
The most important t factor for the people living in volcano prone areas must be
aware and have a check on the emergency alters (Proctor et al., 2018). The government of the
organization must ensure that there is arrangement for people who can easily move to a safer
area that will protect the people from emergency. The people those who have respiratory
issues must ensure that they have their medicines and things that will help them revive from
the difficult situation (Tejedor et al., 2018). People must also ensure that they are in touch
with their family members and in case of emergency in spite of panicking the people must be
calm and find ways to be safe.

5GEOGRAPHY
Conclusion
Hence, it can be concluded that the impact of volcano is massive in the environment
that leads to the downfall of the environmental condition of the organism living around the
areas wherein volcano has been erupted. The various risk factors needs to be identified that
will help in the development of the measures to save life from volcano.

6GEOGRAPHY
Reference List
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(2017, April). Permeability evolution governed by shear: An example during spine
extrusion at Unzen volcano, Japan. In EGU General Assembly Conference Abstracts
(Vol. 19, p. 1425).
Guillet, S., Corona, C., Stoffel, M., Khodri, M., Lavigne, F., Ortega, P., ... & Davi, N. (2017).
Climate response to the Samalas volcanic eruption in 1257 revealed by proxy records.
Nature geoscience, 10(2), 123-128.
Johnson, J. B. (2017). Volcanic Eruptions Repose, and Their Unrest, Precursors, and Timing.
Malavelle, F. F., Haywood, J. M., Jones, A., Gettelman, A., Clarisse, L., Bauduin, S., ... &
Cho, N. (2017). Strong constraints on aerosol–cloud interactions from volcanic
eruptions. Nature, 546(7659), 485-491.
Proctor, J., Hsiang, S. M., Burney, J. A., Burke, M., & Schlenker, W. (2017, December).
Estimating the Global Agricultural Impact of Solar Radiation Management using
Volcanic Eruptions as Natural Experiments. In AGU Fall Meeting Abstracts.
Proctor, J., Hsiang, S., Burney, J., Burke, M., & Schlenker, W. (2018). Estimating global
agricultural effects of geoengineering using volcanic eruptions. Nature, 560(7719),
480-483.
Sato, H., Holtz, F., Botcharnikov, R. E., & Nakada, S. (2017). Intermittent generation of
mafic enclaves in the 1991–1995 dacite of Unzen Volcano recorded in mineral
chemistry. Contributions to Mineralogy and Petrology, 172(4), 22.
Tejedor Vargas, E., Morales, M. S., Christie, D., Andreu-Hayles, L., Villalba, R., Ferrero,
E., ... & Vuille, M. F. (2018, December). South American Altiplano hydroclimate
response to volcanic eruptions over the past 700 years; a first approach using a tree-
ring reconstruction. In AGU Fall Meeting Abstracts.