Nevada del Ruiz

Location: North-west Columbia, South America
Volcano Type: Cone volcano, which is composed by lava domes built within the summit caldera of the older Ruiz volcano. Stratovolcano or composite volcano/
Eruption Type: Explosive, plinian eruption. Formed on convergant plate boundary, as the subduction of the oceanic Nazca plate beneath the continental South American Plate. Hot pyroclastic flows and surges occured. Deadly mudflows and lahars travelled 60 miles, and ejected ash for miles and had a high-volume of debris.
Eruption Frequency: Around 22 eruptions recorded. On average every 10-20 years (1800's but less frequently in recent history)

Eruption History: On 13th November 1985, there was a devastating eruption that killed over 23,000 people.
 

Map of Columbia

Impacts:

Social:

• 23,000+ human deaths
• 15,000 animal and livestock deaths
• 5000 homes destroyed
• Towns buried under layers of ash
• 5000+ people were injured
• 50 educational facilities destroyed
• 2 hospitals destroyed
• 58 industrial plants damaged
• 343 commercial establishments damaged
• Large amounts of Sulphur Dioxide (which is dangerous to humans) was ejected into the atmosphere and reacted with many substances to form sulphuric acid 
  

Nevado del Ruiz

Economic: 

• The region was isolated which meant surrounding regions were unable to provide economical support
• Many buildings were destroyed and damaged which needed clearing, fixing or re-building
• The relief measures would have cost the government a lot to try and resettle the homeless population etc
• Cost for the Columbian economy was £7.7 billion, which was 20% of the GDP for 1985

Environmental:

• Pyroclastic flows melted the summit glaciers and snow, gernerating four thick lahars that raced down river valleys on the volcanoes sides
• Composite volcano shape led to the corroding of a nearby lake and the creation of another lahar. The lake's pH level was 2, showing how sulphur dioxide was creating an acidic solution and causing further damage to the surrounding wildlife
• Farmland was destroyed by the ash, lahars and pyroclastic flow

Lahar = A destructive mudflow on the slopes of a volcano

Political:

• In the first weeks, the relief activities were directed, for the most part, by the Red Cross and then by the Columbian Civil Defence
• About two weeks after the disaster, a presidential task force was created to design and direct a recovery programme

Kilauea

Location: Hawaii
Volcano Type: Shield Volcano
Eruption Type: Hawiian eruptions. Not very explosive or destructive, not as much pyroclastic material. Slow, viscous lava, with low gas content. Sometimes lava fountains are present.
Eruption Frequency: Active volcano, continuous flow of lava since 1983. Total of 61 seperate eruptions recorded
Eruption History: As Above ^

 
 Impacts:

Social:

• People use the volcanic products as construction materials, cleaning agents and as raw materials for many chemical and industrial uses
• Toxic clouds formed called Laze (hydrochloric acid and seawater vapour) and Vog (sulphur dioxide) which can be harmful
• The lava can creep along and destroy or damage homes and land

Economic:

• The steady and consistent flow of lava attracts many tourists each year, so the surrounding towns benefit from the visitors staying -  it increases the local economy
• There is a lot of land which is un-usable due to the lava flows, so the local people are restricted with building
• the locals have a high cost of living

Environmental:

• Can provide electricity by using geothermal energy
• Ash from Kilaeua can over time become beneficial to plant life; as useful minerals inside the ash produce an effective fertiliser
• Land buried by ash, lava or mud, unable to provide growth or sustain life
• Acidic rain destroys land and plant life
• More limiting to animal species - not many can live there

Political: 

• We are sure the tourism generated by the volcanic activity greatly influences the Hawaiin policies, however there is insufficient data to be informed upon this section

Management Strategies:

1. Remove the threat - reinforcing roofs from tephra and ash
2. Disaster preparedness - education, communication and evacuation plans
3. Protection from falling ash - roofs, walkways, specialist canopies
4. Planning for the future - planning, assessing the further danger