paper 1 geophysical hazards

Question 1

Haiti earthquake stats

Answer 1

• 2010
• 7.0 magnitude
• 25km west of Port au Prince
• 13 km below surface
• further aftershocks strong as 5.9, occurring 9 km below surface, 56 km south west of the city
• third of the population of was affected: about 230 000 dead, 250 000 more injured, and around 1 mill homeless
• many of port au prince’s 2 mill residents lived in tin roof shacks perched on unstable, steep ravines
• estimated 3 mill of Haitis population needed emergency aid
• one of the world’s poorest countries and was overpopulated and vulnerable even before the earthquake
• ## only two fire stations and the earthquake degraded an already feeble health service by destroying many hospitals and clinics

Question 2

Christchurch new Zealand stats

Answer 2

• new Zealand’s second largest urban area with a population of 386 000
• 2010 mag. of 7.1
• aftershocks continued into 2012, with the strongest aftershock being of mag. 6.3 occurring in 2011
• relative lack of casualties compared with 2010 Haiti earthquake
• this is due to the earthquake occurring on an early Sunday morning when most people were asleep in their timber-framed homes
• the 2011 earthquake killed 185 people and severely damaged the city
• the 2011 earthquake was smaller in magnitude but deadlier due to the epicentre being closer to Christchurch, shallower (5km) compared to 2010 (10km), occurred on a weekday when CBD was busy, many buildings had already been weakened due to previous earthquakes and liquefaction was significantly greater than during 2010, causing the upwelling of more than 40 000 tonnes of silt

Question 3

mount sinaburg

Answer 3

• volcano in northern Sumatra, Indonesia
• Indonesia located in ring of fire and has 120 active volcanoes
• most active, erupted in 1600 and then was dormant until 2010 and since has been active
• surrounding area was active due to fertile plateau that the volcano helped to form
• since 2010 more than 30 000 villagers have been evacuated (only one death from respiratory problems)
• in 2013 crops failed due to ash fall
• in 2014 eruptions caused the death of at least 14 people
• in 2016 another eruption led to the death of 7 people

Question 4

land slides in Sri Lanka, 2016

Answer 4

• death toll from three days of torrential rain and landslides In Sri Lanka lead to 37 deaths and more than 150 missing people
• rains forced more than 137 people to leave their homes, with those worst affected in central hills
• rescue operations were hard due to treacherous mountain roads
• 100 mm of rain in the space of day
• dozen of houses were destroyed when mountain slopes collapsed, forcing hundreds of villagers to evacuate