Natural Disasters
Is COVID a natural disaster?
1. Based on the definition of a natural disaster being a "calamitous event causing loss of life, damage or hardship" While COVID-19 is not a geologic hazard, I do believe that COVID-19 is a biological hazard that has turned into a natural disaster. Natural disasters occur when hazards, in this case illness, meet vulnerability. We have seen this across in the world through various demographics such as socio-economic status, pre-existing medical conditions, age, gender and race. We can see that the pandemic is a hazard based on the fact that it threatens loss of life, damage or hardship. Some individuals contract the virus and are not impacted any further. However, the natural disaster develops through the more vulnerable populations across the world. Lower economic classes have struggled to get access to adequate health care to treat the virus which has caused more death and hardship when compared to wealthier groups of individuals. More populated areas have also seen more damage and hardship due to lack of resources, more rapid transmission and not enough space in hospitals. Additionally, different races, ages and genders all react very differently to the virus and have seen loss of life, damage and hardship over the past year.
What are three similarities between natural disasters and COVID?
1. both cause loss of life, financial hardship and health 2. cause shortage of supplies and need for government aid 3. causes movement of people or need for shelter
what are the 4 causes of tsunamis?
1. earthquake disrupts the sea floor 2. volcanic eruption 3. landslide associated with the collapse of land into the ocean 4. meteorite impact in the ocean
What are three differences between natural disasters and COVID?
1. natural disasters tend to be one event whereas COVID is ongoing 2. natural disasters tend to cause physical damage to our things whereas COVID causes it only to our health 3. natural disasters are often predictable, COVID is not
dead and affected in haiti
230,000-316,000 died 3 million impacted
what is the viscosity of RHYOLITE
50,000 HIGH thick and sticky
Northridge death and injured
60-70 people died 9000 injured
What is the current global population?
7.7 billion people will reach 8 billion between 2023 and 2024
what is the viscosity of BASALT
80 (very low)
What is the fastest growing country?
Africa with growth rates between 5-10%
what is a grey volcano
DEADLY very ashy (fragments of glass) found in the ring of fire RHYOLITE
what is a shield volcano
GINGANTIC basalt not dangerous HAWAII
Haiti Magnitude and duration
Mag 7.0 duration 30 seconds
What is a tectonic plate and how does it move?
The plates can be thought of like pieces of a cracked shell that rest on the hot, molten rock of Earth's mantle and fit snugly against one another. The heat from radioactive processes within the planet's interior causes the plates to move, sometimes toward and sometimes away from each other
we have understood hazard science and problems associated with disaster vulnerability for a long time and yet we continue to have devastating disasters. Why is this the case?
We continue to have devastating disasters because there is a disconnect between science and the people right now. While we know who the vulnerable populations are and what makes them vulnerable, we are not doing anything to make them any less vulnerable. The lack of collaboration between those experiencing the hardships during disasters and those who are trying to study and plan for the disasters is very present. It is important to go to those people and include them in these processes so that a common outcome can be achieved. This will create more resilient and better prepared communities for when disaster does happen.
Define hazard
a threat; a natural hazard capable of causing danger ex. tornado, earthquake
define resilience
ability to recover quickly and grow from it the people in Haiti are resilient
Northridge fault type
blind thrust fault
Define disaster
calamitous event causing loss of life, damage or hardship; the negative impacts of hazards disasters occur when hazards meet vulnerability ex: Californian wildfires, hurricane katrina
define lava flow
costly not dangerous because so slow
Japan speed of growth
declining population
What are the three types of plate boundaries?
divergent convergent transform
signs of a tsunami
earthquake water retreats into the ocean water is rising, frothing or roaring
Explain the concept: earthquakes don't kill people, buildings do
earthquakes cause shaking but shaking won't kill you. it's the secondary factors that will (buildings falling, liquefaction, etc)
define resonance
eq waves go through buildings, the ground and the earth. if all of these line up, it makes really bad shaking
What is the disaster life cycle?
event response recovery mitigation preparedness
is Africa slowly or quickly growing
fast growth
what disaster impacts the most people
flooding
what is the most common disaster?
flooding
What were the lines of evidence with the 1700 earthquake from the really big one?
found sediment deposits and sea floor samples that suggested it the rings of the trees showed they died that year when the area sank under water sand deposits in Japan showed proof of tsunami
define risk
hazard x exposure x vulnerability OR cost x likelihood
does RHYOLITE have low or high viscosity and velocity
high velocity and high viscocity
define intensity
how the earthquake is felt by people in different areas
what characteristics impact risk
income, health, age, location, socioeconomic status
what is the elastic rebound theory?
it describes sudden fault movement and cause of shaking prior to an eq the fence is straight right before the earthquake the fence begins to being slowly but doesn't break when the eq happens it causes the fence to break and shift
why is the demographic transition model important?
it helps to figure out where the population of a country is at to better address economic and social policies in a country.
Why do the most powerful EQs occur in the ring of fire?
it is a ring of subduction zones where continental plates get stuck on oceanic plates
explain tsunami warning systems DART
it is a surface buoy that is connected to the sea floor and records pressure changes if it senses a pressure change it alerts a satellite that sends a message out to warning systems
define lahar
it's a mud flow not deadly, but very costly cause indirect death through famines flows 12-15mph typically fill valleys and rivers only dangerous if you don't know about it
what happened at Mt. Pelee?
lahars came from the eruption and then pyroclastic flows in town people were supposed to evacuate, but were forced by police to stay because of the election. 29,000 people died, only 2 survived
Describe the Tohoku earthquake
location: east coast of Japan pacific plate subjected below japan magnitude 9.1 800 aftershocks tsunami hit 10-100 minutes after the EQ wave height varied but 128ft at highest moved at 435 mpg caused a nuclear power plant to spill radioactive waste everywhere 15854 deaths 500,000 displaced most expensive disaster in history (429 billion) debris fires homelessness
what is a composite volcano
looks like a volcano (cone shaped) rhyolite ! large! VERY dangerous
Northridge Magnitude and duration
mag 6.7 duration 10-20 seconds
what is a red volcano?
magma fire fountains create lava flows BASALT not dangerous
what 3 factors control intensity
magnitude distance from hypocenter bedrock and soil
define pyroclastic flow
mix of gas and rocks typically from composite volcanoes the most deadly explode and flow SUPER fast. can't outrun them
Why does population matter with regard to natural disasters?
more people means more vulnerability and more exposure to natural disasters
what happened at Tambora?
most violent eruption in the earth's history it lowered global temperatures because the ash blocked the sun lots of harvest failures
what are the causes of earthquakes?
movement of faults is the most common cause testing of bombs underground oil/gas drilling fracking or pumping water back into the ground
what are the 3 types of convergent boundaries?
ocean-ocean ocean-continent continent-continent
what are nearly all volcanoes caused by
oceanic plates sliding beneath continental ones
what is a convergent boundary?
plates collide; the denser one slides below the less dense one destructive, most dangerous create ocean trenches and volcanoes pacific plate
what is a divergent boundary?
plates pull apart from one another bring magma to the surface to fill the gap can cause mountain ranges mostly on ocean floor in the southern hemisphere
what is a transform boundary?
plates slide past one another conservative nothing created or destroyed Haiti, san Andreas, Australia
define viscosity
resistance to the flow of magma (thickness!!) higher viscosity is thicker
how to survive a tsunami 101
run for the hills avoid rivers and bridges climb a building or tree like Spiderman find a raft and paddle like in the hunger games if already at sea take a nice boat ride to deep water don't go back for a beach day after it is over, it will happen again know how to evacuate the city locate your loved ones follow directions of the avengers
What countries are shrinking?
russia and partis of Europe are declining
What are surface waves?
seismic waves that travel along the Earth's surface and cause the most shaking for the longest time
what are the 3 main precursors to volcano eruptions?
seismicity (EQs) deformation snow melt water levels gas emissions small, throat clearing eruptions
• explain the difference between short-term and long-term prediction of earthquakes, including why short-term predictions are not feasible
short term predictions come seconds before it is going to happen. there isn't enough concrete information that cues us into what is going to happen in the short term. all warning signs would be in hindsight long term can be predicted as an estimate through past information that we know or through testing/floor samples, etc.
USA speed of pop growth
slow
what is a scoria cone
small basalt not dangerous short lived
what are the 4 stages of the demographic transition model?
stage 1: birth rates = death rates stage 2: death rates decrease, birth rates are still high at this point which creates rapid growth stage 3: birth rate decreases and gets closer to the death rate which slows growth stage 4: population is stabilized with a low birth rate and low death rate
why are people not prepared for the really big one?
the EQ happened so long ago and nothing has happened since, so it's been pushed aside for the time being
define magnitude
the amount of energy that is released by the earthquake (Richter scale)
define hypocenter
the earthquake happens there
define epicenter
the earthquake is felt there first it is the location above the hypocenter
define velocity
the expansion and release of gases causes violent eruptions due to H20, CO2, SO2
define acceleration
the ground goes from shaking to not shaking. the energy is being transmitted horizontally and increases gradually with shaking
what factors cause populations to increase or decrease
the number of births and deaths each year determines population size
Define plate tectonics?
the outermost layer of earth (lithosphere) is broken into tectonic plates that ride on the weak, malleable layer called the asthenosphere
What is the P wave?
the primary wave that is a little shaking
what is an S wave?
the secondary wave that typically comes before the surface waves. a little stronger than surface waves
define neotectonics
the study of active tectonics with GPS receivers that tell us what direction the plates are moving and how fast
define paleoseismology
the study of old earthquakes to help us understand and predict in the long term new ones aims to fill the gap in knowledge
define amplification
the type of rock in the ground determines shaking softer substances mean more shaking
what happens as a tsunami approaches shoreline?
the wave lengths get shorter as it gets closer to the shore which causes the swell
Eyjafjallajokull: what happened?
they had major and minor EQs or 3 months in 2010 the eruption sent ash 35,000 ft into the air which caused electrical storms, ice caps melted and caused flooding airports had to shut down because of how dense the ash was costly ($1.7 billion)
what is the difference between wind generated waves and tsunamis?
wind generated move 5-65 mph and have short wavelengths of 300-600ft tsunamis move at 500-600mph in the deep ocean and their wavelength is 60-300 miles long
