EARTHQUAKES, examples and when to use them

When/where was the Sulawesi + magnitude?

(28th Sept) 2018

Focus on Palu (Indonesia) Transform boundary

7.5 magnitude

What does the Sulawesi show?

• Unexpected tsunami from a transform boundary.

• Landslide caused by a quake, caused tsunami.

• Liquefaction on a slope.

• 4,340 dead

When to use Sulawesi

• Are some boundaries more dangerous than others counter argument.

• Good e.g. if how a landslide can be catastrophic (mass movement + tectonic).

• Good e.g. of it causing a mudslide (mass movement + tectonic).

• Good for how liquefaction could be most significant hazard.

• Helpful differentiation between tectonic related mudslide and lahar.

When/where was the Christchurch + magnitude?

(22 Feb) 2011

(NZ) Transform boundary

6.4 magnitude 5km depth

What does the Christchurch show?

• Damage from liquefaction.

• Building codes only for shaking prior to quake.

• Type of sediment (silty) exacerbated liquefaction.

When to use Christchurch?

• length of recovery from liquefaction (drainage systems, structures, roads).

• E.g. of changing response - new building codes to include liquefaction measures (disaster response plans, building back better, Park model).

• Physical reason (geology) why moment magnitude scale score doesn’t match with Richter scale.

• Earthquake in 2010 - still lots of structural damage.

When/ where was Nepal + magnitude?

(25 April) 2015

Convergent boundary

7.8 magnitude 8km depth

What does Nepal show?

• Landslide damage.

• Area of outmigration (male economically active in Middle East providing labour for booming building industry).

• Avalanche (killed 19 people at Everest base camp).

• approx. 9,000 dead

When to use Nepal

• Demonstrates how the landscape can increase vulnerability.

• Case study of landslides (mass movement (mm) hazard).

• Landslides blocked roads and limited infrastructure meant no alternatives. This hampered rescue in remote villages.

• Lack of skilled construction workers hampered rebuilding process.

• Avalanche good mm case study for secondary hazard.

When/where was Tohoku, Japan + magnitude?

(11 march) 2011

Convergent boundary

magnitude 9 29km depth

What does Tohoku, Japan show?

• Powerful shaking but limited urban damage.

• Tsunami 40m high, 10km inshore flow.

• 18000 deaths.

• Nuclear reactor disaster of Fukushima.

When to use Tohoku, Japan.

• Effective mitigation against primary hazards.

• E.g. of inability to mitigate against nature.

• Warning systems function but proximity of faultline left not enough time.

• Complacency of population (everyone within 11 minutes of shelter but only had 6 mins).

• Even wealth and development don’t guarantee survival.

• Long term impacts - national disclination to continue with nuclear path, alternatives?

• Lack of energy shut down resulted in suspended production of many component factories. This resulted in global shortage.

When/where was Haiti + magnitude?

(12 Jan) 2010

Transform thrust fault

magnitude 7 13km depth

What does Haiti show?

• Poorest country in western hemisphere.

• Catastrophic Mercalli score and death toll.

• Cholera outbreak.

• Damage to infrastructure and loss of command posts.

• Had received info from USGS that stress was building - couldn’t do anything with the info.

When to use Haiti?

• Inability to prepare and respond.

• Vulnerability can be so extreme that even a ‘limited hazard’ can be catastrophic.

• Long term impact.

• Large international response but poorly coordinate, delay in distribution (+ liquefaction at port).

When/ where was Sichuan + magnitude?

(12 May) 2008

(China) Collision boundary

magnitude 8 19km depth

What does Sichuan show?

• Not sticking to national building codes in 2008 (schools collapsed - children died - protests).

• Seismic gap theory was successful when scientists predicted that a segment 60 miles away would move about 5yrs after the 2008 one. Authorities didn’t listen and in 2013 there was an earthquake precisely on that segment and 200 people died.

When to use Sichuan?

• Having mitigation strategies is one thing but must be implemented.

• Prediction and protection may exist but if it doesn’t filter down locally and if authorities don’t act on it then its is ineffective.