geography natural hazards

natural hazards

extreme naturally occurring events that can cause loss of life and injury, damage to property and disrupt human activity

types of hazards

tectonic, climatic, hydrological and biological

factors affecting hazard risk

population growth and density, development, climate change, poverty, magnitude and frequency of the event, response

theory of plate tectonics

the theory of plate tectonics states that the earth’s lithosphere is broken down into large, rigid slabs of rock called tectonic plates. the tectonic plates float and slowly move across the asthenosphere.

destructive plate margin

a destructive plate margin usually involves an oceanic plate and a continental plate. the plates move towards each other and this can cause earthquakes.

constructive plate margin

at a constructive plate margin the plates move apart from one another. when this happens the magma from the mantle rises up to construct new land in the form of a shield volcano. the movement of the plates over the mantle can cause an earthquake

conservative plate margin

at conservative plate margin, plates move past each other or side by side at different speeds. this causes friction to occur and the plates become stuck, which causes pressure as the plates are still trying to move. pressure builds up and when the pressure is released, it produces huge amounts of energy which can cause an earthquake

primary effects of natural hazards

loss of life and injuries, destruction of buildings and homes, damage to transport infrastructure, disruption of utilities, environmental and agricultural damage

secondary effects of natural hazards

disease outbreaks, famine and malnutrition, economic collapse, homelessness

immediate responses to a long term natural hazard

search and rescue, evacuating people, temporary shelter, medical care

long term responses to natural hazards

rebuilding infrastructure, restoring utilities, rehousing people, risk mitigation and planning, economic recovery

how do the affects and responses to a natural hazard differ between two areas with contrasting levels of wealth

• in 2015 in the Kathmandu area of Nepal, an LIC, an earthquake which had a magnitude of 7.8 left 9000 dead, 22000 injured, and destroyed historic temples and over 600,00 homes. For the first 24 hours after the event, there was no aid sent as its isolated location and poor transport links made it difficult for aid organisations to reach the area quickly. After a few days, international aid arrived from the UK, India and China. they brought search and rescue teams and medical support around £87 million was raised through donations. Nepal relied heavily on international relief as being an LIC, they did not have the funds to support themselves. This severely stunted responses to the event and so it resulted in far more devastation than what would’ve occurred at a HIC or NEE

• for example, in Japan (an HIC) in 2011, a 9.0 magnitude earthquake struck Sendai Bay. However, despite the magnitude and force of the earthquake, there were only around 700 deaths, far less than in Nepal with a magnitude of 7.8. Although devastation wasn’t obsolete, Japan managed the situation better due to its economic prowess as an HIC.

why do people continue to live in areas at risk of tectonic hazards

there can be economic benefits such as volcanoes attracting tourism, and mining resources. there can also be social reasons, such as familial and cultural ties, and practical reasons such as financial constraint and poverty

how does monitoring help manage tectonic hazards

scientists use specialised and scientific instruments to continuously track environmental and geological changes. these include seismographs for earthquakes and tiltometers for volcanoes

what is the global atmospheric circulation model

the large-scale movement of heat energy around from the equator to the poles

distribution of tropical storms

tropical storms are found exclusively in tropical and subtropical regions, mostly occurring 5 to 30 degrees north and south of the equator

how are global atmospheric circulations and the distribution of tropical storms connected

they are closely connected through the Hadley cell, surface trade winds and and the Coriolis effect