Deck 5a - Tectonics: Mt.Nyiragongo, DRC Flashcards

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1
Q

What year was the Mount Nyiragongo eruption?

A

2002

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2
Q

What time did the Mount Nyiragongo eruption occur?

A

9:30am

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3
Q

What hazards were caused by the Mount Nyiragongo eruption?

A

Lava flow, ash, gases

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4
Q

What type of plate boundary is Mount Nyiragongo on and which tectonic plates are involved?

A

Constructive boundary that forms part of the East African Rift Valley. The African plate (also known as the Nubian Plate) in the west is splitting from the Somali plate in the east.

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5
Q

What type of volcano is Mount Nyiragongo?

A

Composite

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6
Q

What sort of magma does Mount Nyiragongo produce and what sort of eruptions does this lead to? Why?

A

Mafic/basaltic because it is located on a constructive plate margin meaning as the Nubian and Somali plates are pulled apart magma rises to to surface in between. As such the magma has not had time to evolve producing a mafic magma. This results in effusive eruptions with lava with a low viscosity as gas is able to escape readily.

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7
Q

How frequently does Mount Nyiragongo erupt?

(FREQUENCY)

A

34 times since 1882 averaging approximately once every 30 years.

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8
Q

What was the VEI of the Mount Nyiragongo eruption?

(MAGNITUDE)

A

VEI = 1

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9
Q

What was the duration of the Mount Nyiragongo eruption?

(DURATION)

A

1 day, 17th January 2002

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10
Q

What signs were there before the Mount Nyiragongo eruption occurred?

(PREDICTABILITY)

A

Harmonic tremors were felt though were not acted on.

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11
Q

How quickly did the Mount Nyiragongo eruption occur?

(SPEED OF ONSET)

A

The lava travelled rapidly at 60km/hour leaving just 30 minutes until it reached Goma. Within a few hours of the eruption starting a 13km fissure had opened with 3 main vents.

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12
Q

What area did the Mount Nyiragongo eruption impact?

(AREAL EXTENT)

A

Covered 4.7 km2 including 80% of the city of Goma

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13
Q

What was the GNI of the DRC before the Mount Nyiragongo eruption?

(ECONOMIC vulnerability)

A

$190 per capita in 2002

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14
Q

What was the level of technology available in the DRC during the Mount Nyiragongo eruption?

(ECONOMIC vulnerability)

A

Limited technology, very small team of geologists

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15
Q

How educated were the DRC’s population about the risks of volcanic eruptions prior to the Mount Nyiragongo eruption?

(SOCIO-ECONOMIC vulnerability)

A

Primary and secondary education enrolment has remained a serious issue since the DRC gained independence in 1960 largely due to costs associated with attending such as access to competent schools, funds for supplies. Enrolment rate is 40% in primary and secondary schools and is lower in areas of conflict such as Goma.

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16
Q

What was the population structure of the DRC before the eruption?

(SOCIAL vulnerability)

A

-DRC has a youthful population with a high birth rate (42 per 1000 people)
-Low population density in rural areas surrounding Goma but a high population density in the city itself

17
Q

How stable is the DRC’s government?

(POLTICAL vulnerability)

A

Historically the DRC is a unstable country due to conflict between opposing groups about how to run the country since it gained independence from Belgium in 1960. This resulted in a poor government due to ongoing wars and civil unrest due to disagreements between rebels and the government. Government officials were found to be highly corrupt and working with rebel groups.

18
Q

What were the economic impacts of the Mount Nyiragongo eruption

A

-$9bn damages
-80% of Goma destroyed
-4,500 buildings destroyed including 50% of hospitals
-Lava destroyed runway at Goma airport
-Tourist trade collapsed

19
Q

What were the social/demographic impacts of the Mount Nyiragongo eruption?

A

-147 dead
-400,000 evacuated
-120,000 homeless
-Thousands of refugees fled to Rwanda but were not welcomed
-Looting took place

20
Q

What are the environmental impacts of the Mount Nyiragongo eruption?

A

-Lava destroyed vegetation and local ecosystems
-Increased acidity of Lake Kivu

21
Q

How prepared was the DRC for the Mount Nyiragongo eruption?

A

-Lack of education about hazards in place and last eruption was 25 years prior (1977)
-Warnings from early tremors and 2 scientists were not acted on

22
Q

What was the response (short term) to the Mount Nyiragongo eruption?

A

-Evacuation of 300,000 but only where lava was engulfing the area and was hindered by the closure of the airport
-Aid agencies launched short term food, water and shelter support but outside aid was limited due to corruption
-Lava and ash was cleaned from the streets

23
Q

What was the recovery (long term) to the Mount Nyiragongo eruption?

A

-The UN (United Nations) set up long term camps for displaced people with the UNHCR (United Nations High Commissioner for Refugees) supporting over 1,300 families
-15 years later the city had grown to be larger than before the eruption and is home to over 1 million. Houses, hotels, shops, roads were reconstructed and built on top of the solidified lava rock

24
Q

What was the mitigation after the Mount Nyiragongo eruption?

A

-Educational campaigns in schools and public informed about future risks
-Improved monitoring of geophysical and chemical readings and a Volcano and Environmental Risk unit opened (with support of US Geological Society)