Reducing the Impact of Earthquakes & Volcanoes | Geography for GCSE/IGCSE - Year 11 PDF Download

Introduction

The ways to minimize the effects of earthquakes and volcanic eruptions can be categorized as short term or long term responses.

• Short term responses occur immediately after an event, encompassing aid delivery and disaster relief efforts.
• Long term responses are geared towards lessening the impact of future hazard events, involving risk evaluations and hazard mapping.

Earthquakes - long term responses

• While accurately predicting earthquakes remains a challenge, monitoring efforts play a crucial role in enhancing our understanding of seismic activity.
• Various methods are employed to monitor earthquakes and explore potential prediction strategies:
  • Tiltmeters: These devices track ground movements, providing insights into potential seismic shifts.
  • Clusters of Small Earthquakes: Monitoring small seismic events can offer valuable data on larger earthquake patterns.
  • Changes in Radon Gas Emissions: Fluctuations in radon gas levels can sometimes indicate seismic activity.
  • Changes in Animal Behavior: Observing how animals react to environmental changes can offer early earthquake warnings.
  • Remote Sensing Using Satellites: Satellite technology aids in monitoring ground movements and seismic precursors from a distance.
• In developed nations, architectural practices and engineering solutions are commonly employed to mitigate earthquake impact.
• Building regulations mandate the inclusion of earthquake-resistant features in new constructions:
  • Shutters on Windows: Installing protective shutters helps prevent glass from shattering during seismic events.
  • Cross-Bracing of Steel Frames: Strengthening structures with cross-bracing enhances their resilience against tremors.
  • Flexible Building Materials: Using materials that can withstand seismic stressors improves building durability.
  • Foundations Sunk Deep: Buildings anchored in the bedrock are more stable during earthquakes.
  • Frames Designed to Sway: Structures with flexible frames can better absorb earthquake vibrations.
  • Rubber Shock Absorbers: Integration of shock-absorbing materials reduces tremors transmitted through buildings.
  • Reinforcement of Walls and Pillars: Strengthening key structural elements like walls and pillars enhances overall stability.
  • Shatterproof Glass: Installing reinforced glass minimizes the risk of breakage during seismic events.
  • Fire-Resistant Materials: Using fire-resistant materials helps prevent additional hazards post-earthquake.
  • Automatic Gas/Electricity Cut-off: Automated systems that shut off gas and electricity minimize fire risks.
• Regular earthquake drills conducted in many countries
• Drills aiding individuals in preparing for earthquake responses to ensure personal safety
• Education on home preparation reducing the risk of injuries from falling objects

Volcanoes and earthquakes - long term responses

• Planning in areas prone to earthquakes and volcanic eruptions involves utilizing various strategies to mitigate risks and ensure sustainable development.
• In vulnerable areas:
  • Remote sensing, like through Sentinel 1 satellites, offers crucial insights into ground movements, aiding in risk assessment and monitoring.
  • Geographic Information Systems (GIS) play a pivotal role by providing detailed data layers on 
    • Vulnerable Areas
    • Land Use
    • Infrastructure such as Roads
  • GIS Data Usage in Land Use Planning
  • Land Use Planning
    • Mapping of Areas Most at Risk from Earthquakes
    • Ensuring Services like Fire Stations and Hospitals are Away from High-Risk Zones
    • Locating Densely Populated Housing Away from High-Risk Areas

Case Study: Nepal

• Nepal, positioned between China and India, stands out as one of the world's most impoverished nations, boasting a Gross Domestic Product (GDP) per capita below $1000.
• The country is landlocked, limiting its accessibility to maritime trade routes and impacting its economic development.
• By 2015, a significant 80% of Nepal's populace resided in rural regions, often isolated and distant from urban centers.
• In April 2015, at 11.26 am, Nepal faced a catastrophic earthquake measuring 7.8 on the Richter scale.
• The earthquake's epicenter was situated 80 km northwest of Kathmandu, specifically in the Gorka district.
• Notably, the earthquake's focal point was shallow, merely 15 km beneath the earth's surface, triggering over 300 subsequent aftershocks.
• Location of Nepal Earthquake:
  

Causes

• Nepal is situated at a convergent boundary where the Indian and Eurasian tectonic plates collide, leading to seismic activities like earthquakes.

Impact of the Disaster

• Approximately 9000 deaths
• Over 20,000 people injured
• Electricity and water supplies disrupted
• 7000 schools and 1000 health facilities damaged or destroyed
• Almost 3.5 million people left homeless
• Offices, shops, and factories destroyed, affecting livelihoods
• UNESCO world heritage sites and temples destroyed
• Loss of tourist income, a significant source of revenue
• Avalanches on Mount Everest and in the Langtang Valley
• Landslides blocking roads and rivers
• Estimated damages between $7 and $10 billion, around 35% of the GDP

Relief Efforts

• Donations of money and aid totaling $3 billion from around the world
• Specific aid in the form of temporary shelters, medicines, food, water, clothing, search and rescue teams, and medical staff
• 90% of the Nepalese army mobilized for assistance
• Tent cities established in Kathmandu for the homeless
• Utilization of GIS crisis mapping tool for effective coordination
• $3 million grant provided by the Asian Development Bank for emergency relief

Emergency Response to Nepal Earthquake

• Provision of Immediate Support:
  • Provision of temporary shelters for the affected population
  • Distribution of essential medicines to medical facilities
  • Supply of food and clean drinking water to ensure basic sustenance
  • Distribution of clothing to protect from the elements
  • Deployment of search and rescue teams to locate and aid survivors
  • Mobilization of medical staff to provide healthcare services
• Assistance from the Nepalese Army:
  • 90% of the Nepalese army was activated to assist in the relief efforts
  • Establishment of tent cities in Kathmandu to accommodate displaced individuals
• Utilization of Technology for Coordination:
  • Implementation of a GIS crisis mapping tool to coordinate the response effectively
• Financial Aid and Reconstruction:
  • Emergency relief grant of $3 million from the Asian Development Bank
  • Allocation of $200 million by the Asian Development Bank for reconstruction efforts
• Rehabilitation and Preparedness Measures:
  • Clearing of landslides and repair of roads to restore access to remote communities
  • Reconstruction of schools to ensure continuity of education
  • Introduction of earthquake drills to educate people on safety measures
  • Implementation of stricter building codes with enhanced enforcement
  • Formation of a government task force to strategize for future earthquake events

Case Study: La Palma

• La Palma, a part of the Canary Islands, is situated in the Atlantic Ocean near North Africa.
• The Canary Islands form an autonomous region of Spain.
• There are a total of 33 volcanoes in the Canary Islands, with 10 of them located in La Palma.
• La Palma has a population of approximately 85,000 residents.
• In September 2021, the eruption of the Cumbre Viejo volcano on La Palma began and lasted for nearly three months.
• The eruption was classified between VEI 2 to VEI 3 on the Volcanic Explosivity Index.
• Location of Cumbre Viejo Volcano:
  

Causes

• La Palma and the other Canary Islands are situated on the African plate.
• The islands form an archipelago resulting from a hot spot, not a plate boundary.
• This implies that they are situated not at a tectonic plate boundary but rather above a magma plume.

Signs of eruption

• Deformation of the mountain indicated magma rise a week before the eruption.
• Between September 10-19, there was a significant 'earthquake swarm' with over 25,000 earthquakes.

Impact of the Eruption

• More than 7,000 individuals were evacuated from their homes.
• Close to 1,500 houses were destroyed by the lava flow.
• Over 1,500 other structures like churches, shops, and schools were also destroyed.
• The lava flow crossed the coastal highway, disrupting traffic.
• Water supply was interrupted for nearly 3,000 people.
• Approximately 400 hectares of banana farms were devastated.
• Almost 1,300 hectares of land were affected by the eruption.
• There was one fatality reported.
• About 20,000 individuals experienced the eruption's effects.
• Air traffic was disrupted, and damages amounted to €1 billion.

Immediate response

• A warning was issued on September 13, leading to the evacuation of 40 people and livestock.
• Following the eruption on September 19, an additional 1000 individuals were evacuated.
• Over the subsequent weeks, 5600 more people were evacuated due to the escalating situation.
• The alert level was raised to red, signifying the severity of the eruption.
• Air traffic was temporarily halted to ensure public safety.
• Ongoing monitoring of lava flow and gas emissions was conducted to protect the population.
• Essential provisions such as food and shelter were provided to those displaced by the eruption.
• An advanced payment of €5.4 million was donated by the EU to aid in recovery efforts.

Long term response

• Spain pledged €400 million to support the reconstruction of La Palma following the disaster.
• Prefabricated housing was erected for those left homeless, but many continued to reside in temporary accommodations months later.
• Continuous monitoring of the volcano and others on La Palma was established to mitigate future risks.
• Enhanced crisis management strategies have been implemented to better prepare for potential future eruptions.