Tectonic Processes and Hazards Flashcards
What was the death toll of the 2011 Tohoku earthquake and tsunami?
Over 20,000 people.
Why was the death toll of the 2011 Tohoku earthquake and tsunami so high?
40-meter tsunami overwhelmed coastal defenses.
How many people died in the 2010 Haiti earthquake?
Around 230,000 people.
Why did the 2010 Haiti earthquake result in such a high death toll?
Poorly constructed buildings collapsed easily.
How many relief workers were deployed after the 2008 Sichuan earthquake in China?
130,000 people.
Why was the response to the 2008 Sichuan earthquake so large?
Magnitude 7.9 required massive aid.
What was the estimated death toll from the 2004 Indian Ocean tsunami?
Around 230,000 people.
Why did the 2004 Indian Ocean tsunami cause such widespread destruction?
Waves traveled 800 km/h across countries.
How many people died in the 2011 Christchurch earthquake in New Zealand?
185 people.
Why was the 2011 Christchurch earthquake so deadly?
Shallow depth caused severe shaking.
What was the death toll of the 1995 Kobe earthquake in Japan?
6,434 people.
Why did the 1995 Kobe earthquake cause such a high death toll?
Magnitude 7.2 caused widespread collapse.
How many people died in the 2010 Mount Merapi eruption in Indonesia?
353 people.
Why did the 2010 Mount Merapi eruption cause significant fatalities?
Pyroclastic flows moved at 100 km/h.
How many people were evacuated before the 1991 Mount Pinatubo eruption in the Philippines?
200,000 people.
Why was the evacuation before the 1991 Mount Pinatubo eruption so successful?
Early warning helped avoid casualties.
What was the population affected by the 1995 Montserrat volcanic eruption?
Two-thirds of the population evacuated.
Why did two-thirds of Montserrat’s population evacuate during the 1995 volcanic eruption?
Intense eruptions prompted large-scale evacuation.
How much seawater was used to cool lava during the 1973 Eldfell eruption in Iceland?
6.8 billion litres.
Why was 6.8 billion litres of seawater pumped during the 1973 Eldfell eruption in Iceland?
To cool lava and protect infrastructure.
What is the estimated economic loss expected from a future major earthquake in San Francisco?
$200 billion.
Why would a future major earthquake in San Francisco result in $200 billion in economic losses?
High property values, dense population.
How many countries are covered by the Pacific Tsunami Warning Center (PTWC)?
28 countries.
Why does the Pacific Tsunami Warning Center cover 28 countries?
Tsunami threats affect many coastal nations.
How many people died in the 2015 Afghanistan earthquake?
Around 400 people.
Why was the death toll in the 2015 Afghanistan earthquake relatively low?
Sparse population limited fatalities.
How many people died in the 2003 Bam earthquake in Iran?
Over 26,000 people.
Why did the 2003 Bam earthquake result in such a high death toll?
Collapsing buildings caused mass casualties.
How many people died in the 1999 North Anatolian Fault earthquake in Turkey?
Around 17,000 people.
Why was the 1999 North Anatolian Fault earthquake so deadly?
Magnitude 7.6 caused widespread destruction.
How many volcanic explosions occur annually at Sakurajima in Japan?
Up to 1,000 explosions.
Why does Sakurajima experience up to 1,000 volcanic explosions annually?
Continuous volcanic activity, frequent eruptions.
How many people died in the 1991 eruption of Mount Pinatubo in the Philippines?
Around 800 people.
Why was the death toll from the 1991 eruption of Mount Pinatubo relatively low?
Successful evacuation minimized fatalities.
How many people died in the 1992 Mount Etna eruption in Italy despite the use of lava diversion techniques?
Zero casualties.
Why were there no casualties during the 1992 Mount Etna eruption?
Lava diversion techniques redirected flows.
What are mega-disasters?
Large-scale disasters by areal extent.
What else defines mega-disasters?
Economic or human impact.
How does tectonic setting influence hazards?
Affects magnitude, frequency, and type.
Where do 90% of tsunamis occur?
90% in the Pacific Ocean.
How does the Pacific affect vulnerability?
Increases regional vulnerability.
What is the result of destructive (convergent) margins?
More explosive volcanic activity.
Why is volcanic activity more explosive at destructive margins?
Andesitic lava with higher gas content.
What happens at constructive margins?
Less explosive basaltic eruptions.
How do hotspots affect eruptions?
Produce less explosive basaltic eruptions.
Example: Hawaii.
Why are island arcs more hazardous?
Water-bearing sediments increase volatiles.
Give an example of a hazardous island arc.
Montserrat.
What are the types of volcanic hazards?
Lava flows, pyroclastic flows, ash falls.
What other volcanic hazards exist?
Gas eruptions, lahars, jökulhlaups.
What factors are considered in hazard profiles?
Magnitude, speed of onset, areal extent.
What else is considered in hazard profiles?
Duration, frequency, spatial predictability.
How do shallow-angle faults affect hazard impact?
Affect larger areas, amplify impacts.
Give an example of a shallow-angle fault.
Afghanistan 2015.
What are blind faults?
Faults with unpredictable behavior.
Give an example of a blind fault.
Kobe 1995.
How does governance affect vulnerability?
Through monitoring, education, mitigation strategies.
What does strong governance improve?
Disaster response and recovery.
What does weak governance reduce?
Effectiveness of building codes, planning.
What limits governance in some areas?
Affordability and budget constraints.
Where can weak governance occur?
In both developed and developing countries.
What is the hazard management cycle?
Response, recovery, mitigation, preparedness.
Who influences hazard management?
Both government and community-led strategies.
What limits long-term hazard management?
Affordability of measures like aseismic buildings.
Can earthquakes be predicted?
Earthquakes can be predicted spatially.
How are tsunamis detected?
After earthquakes, warnings are issued.
Example: PTWC, 2009 Pacific tsunami.
What limits prediction accuracy?
Extreme events may overwhelm predictions.
Example: Tohoku 2011 tsunami.
What do scientists study for earthquake prediction?
Stress accumulation on faults.
Give an example of a studied fault.
North Anatolian Fault.
Are volcanic locations well-known?
Yes, volcanic locations are generally well-known.
How does monitoring equipment help manage volcanoes?
Portable equipment improves management potential.
What happens if prediction strategies fail?
Magnitude may exceed expectations, defenses inadequate.
What affects social vulnerability?
Population density, isolation, urbanization.
What other factors affect vulnerability?
Inequality of access to housing. Access to education, healthcare, income.
How does high population density affect vulnerability?
Amplifies even low-magnitude impacts.
How does remoteness affect hazard response?
Remote areas are harder to reach.
Why are poor communities more vulnerable?
Lack of resources to evacuate.
How does inequality affect resilience?
Influences access to mitigation tools.
How does urban infrastructure affect vulnerability?
Affects exposure and recovery time.
What strategies modify tectonic events?
Land-use zoning, hazard-resistant design. Engineering defenses, lava diversion.
What strategies modify vulnerability and resilience?
Monitoring, prediction, education. Community preparedness.
How can loss from disasters be modified?
Emergency aid, recovery aid. Insurance, community-led recovery.
Which volcanic hazards are manageable?
Lava flows (e.g., Eldfell 1973). Lava flows (e.g., Mt. Etna 1992).
Which volcanic hazards are hard to manage?
Pyroclastic flows, blast waves.
What affects the effectiveness of hazard management?
Hazard type, frequency, tectonic setting.
How does development level affect hazard management?
Influences access to mitigation tools.
Example: Zoning, shelters in Japan.
How do developed areas compare?
They have stronger monitoring systems. Better education and insurance.
How does community resilience reduce vulnerability?
Better healthcare, housing, and income.
How do frequent events improve responses?
Areas with frequent events develop better responses.
Example: Merapi as Decade Volcano.
How is hazard management effectiveness measured?
By death and injury counts. Economic losses, recovery speed.
How are high-magnitude events managed?
Harder to manage even in developed nations.
Example: Japan 2011.
Can smaller events cause major damage?
Yes, in vulnerable, unprepared regions.
Example: Haiti 2010.
How does development affect hazard management?
Affects preparation, response, and reconstruction.
