GEOL265 case stud

landslides causing tsunamis

1883 Krakatau (Indonesia) eruption caused a tsunami that killed 36000. 2018 krakatau landslide + tsunami that killed hundreds. hawaiian landslides

auckland volcanic field

low likelihood of explosion but high population of people makes it a big risk. many small and scattered volcanoes. small ones don’t re erupt but new ones will form by eruptions

taupo volcano

one large, central volcano that has erupted many times and will erupt again. most eruptions are much smaller and more common

1985 armero, columbia explosion

failures of communication left 23,000 dead

marlborough fault

crutsal fault, horizontal movement and uplift

chile 1960 earthquake

M: 9.5, 30m slip displacement, 1000km fault rupture

1906 san adreas fault

400km of fault rupture, 7.8 magnitude

M7.1 2010 Darfield Earthquake

large ground rupturing earthquake on a previously unknown fault

Canterbury earthquake sequence

many aftershocks, …

earthquake generated landslides

seafront landslide after M7.8 2016 Kaikoura earthquake(triggered many), apline fault generates landslides(cascade rock avalanche deposit)

anthropogenic landslides

vajont dam and lake: water builds on steep slope=instability + failure, abbotsford landslide, dunedin 1979: deforestation, cut slope, poor geology

abbotsford landslide 1979

poruous green island loose sandstone on top of abbostford mudstone which is very weak when wet, water passed through and clogged mudstone was very unstable, dip slope, humans dug along base of hill, burned native forest so no trees to hold ground together or absorb water, after sever rainfall extremely unstable ground

historical nz tsunamis

1947 Tatapouri tsunami(6-10m run up), distant M9.5 1960 valdiva, chile earthquake, fiordland 2003 earthquake caused landslide caused tsunami, cook strait canyon: large submarine landslides that would have caused tsunamis, 1855 wairarapa earthquake caused 8m run up

1947 tatapouri tsunami

many earthquakes caused long period of shaking triggering tsunami, locally damaging

largest earthquake in the world

M9.5 1960, Chile earthquake caused 2000km of rupture, traveled 10000km

cook strait canyon

large submarine landslides that would have caused tsunamis

2016 kaikoura earthquake tsunami

6-7m run-up in goose bay with crustal fault with significant vertical displacement, not a subduction zone

cyclone gabrielle

very wet summer meant less water capacity in catchment, narrow and short catchment increased speed, cleared pine decreased capacity of soil to store water

Aral sea

world’s 3rd largest lake in central asia, river diverted for irrigation, poor canals and water loss, volume decreased and salinity increased, fisheries collapsed, no longer connects to sea, is in two parts, 5 million people health impacted, 100,000 displaced, lot of disease

hurricane katrina 2005

storm surge associated was over 9m which is category 5 even though hurricane was a category 3 in louisiana, made a cat 1 landfall in florida before

sharpiegate

trump insisted that hurricane dorian would reach alabama, caused a lot of confusion and people unsure of where to evacuate, never got even close to alabama

Taiwan 1999

multiple hazards, weak sediment deposits, convergent boundary, tropical climate, rainy season with east asian monsoon and high typhoon frequency. chi-chi earthquake 1999 of M7.6, killed 2400(2nd deadliest in Taiwan) caused 26000 landslides, very damaging 100,000 buildings destroyed or severely damaged. cat 5 typhoon prior caused 9.77km of landslides, cat 3 typhoon after with 1200mm less rainfall caused 48.8km of landslides(x5 herb)

chernboyl 1986 in USSR/Ukraine

31 direct deaths, 15 indirect, 350,000 displaced. ongoing problem, bankrupted soviet union. experiment gone wrong where workers were unfamiliar with planning and procedures. power decreased making it unstable increased steam, blew roof off and release radioactive dust. contaiminated regions focused in areas where it rained(natural vector of wind and rain), health disorders and decrease in birth rates, bioaccumulation in the food chain. had to build containment structures, built a new one, requires active management for millenia

Exxon Valdez 1989

big oil spill(10.8 million gallons) was transported very far and across many coastlines due to sea vector, alaskan coastal current

Deepwater Horizon 2010

210 million gallons of oil, hurricane pushed oil onshore louisiana, concern that circular current in gulf of mexico would circulate it across the entire gulf but luckily it never reach it

Fukushima 2011

hazard incoporated into planning insufficently, it was preventable but the sea walls were too low, M9.0 earthwauke triggered 10km inland tsunami that overtopped seawall, caused shutdown and triggered backup generators but tsunami damaged pumps and backup generators leading to insufficient cooling and 3 nuclear meltdowns and a hydrogen air explosion releasing radioactive material into the air and water. cooling with helicopters dropping sewater, cost 50 billion, excess water use and contaimnated waater speeage into the land must be stored and treated and is an ongoing issue. no radiation fatalities but 55 from evacuation and later fatalities from cancer. all nuclear in japan shut down post disaster, 54 to 13 plants now and there are very high safety measures so new ones not being built(very expensive), new focus on coal. radioactve leaked into the ocean and spread to the US and up to Alaska increasing radiation in tuna. was not enough to harm humans, plants or animals but if more radiation happened in a future disaster it could reach the whole world

Queenstown lakes District Council Fault Study

coming up with multi-hazard and risk study for 3 years. Focus on earthquakes and earthquake generating landslides and understanding the faults. Rapid growing area in queenstown and wanaka. Nevis-Cardrona fault passes through wanaka and frankton, will shake for 40 seconds but be very strong and damaging. high earthquake and landslide hazard with steep and unstable terrain. alpine and pisa fault nearby.

Katrina recovery

different for different groups, old, ill poor and minorities had increase social vulnerability, historical redlining and jim crow had racism negatively impacting recovery by influencing resource access. Affluent areas redeveloped faster(more access to resources, more education), slow return of infrastructure to the poorest areas. resistance by government to rebuild public housing, low income had less capacity to return because housing was competitive

Franz josef case study

glacier tourism reliant. Alpine fault earthquake hazard of mag 8 risk through town, glacier retreat making rockfall likely and high flood risk. community pushback to risk mitigation, hazard engagement requires public engagement and scientists. options are to move town to lake, remove key assets and let river run free, remove gravel and add stopbanks