earthquakes Flashcards
(22 cards)
what is the point inside the earths crust where the earthquake originates from
the focus
what are seismic waves
The earthquake’s energy is released in seismic waves, which spread out from the focus. The seismic waves are most powerful at the
epicentre
what is the point directly above the focus
the epicentre
are earthquakes found at all three boundaries (divergent , convergent and conservative)?
yes
what is the richter scale
the measure by which the strength of the earthquake is determined
elaborate on what the richter scale does
measures the magnitude of an earthquake . its measured usinf a machine called a seisometer which produces a seismograph . - the RS is normally numberes from 1-10 though there is no actual limit
what is the new scale used by scientists to measure earthquakes
the moment magnitude scale
elaborate on the moment magnitude scale
The moment magnitude scale is a measure of an earthquake’s magnitude based on its seismic moment.
define the affect of an earthquake
the damage which happens as a result of the earthquake.
factors affecting the effect of an earthquake
The size of the earthquake on the Richter scale - the higher on the scale, the more destruction it causes.
Level of development - whether it occurs in a rich or a poor country. Richer countries will be more likely be able to predict, protect and prepare themselves from the effects of an earthquake.
The depth of the focus - if it’s shallow, it can be more destructive.
Distance from epicentre - the effects of an earthquake are more severe at its centre.
Population density - the more people living in an area, the more likely that more deaths and casualties may arise.
The time of day whether people are in their homes, work or travelling.
what are the 2 categories used to classify affects of an earthquake
primary effect - things that happen immediately as a result of an earthquake
secondary effects -things that happen in the hours, days and weeks after the initial earthquake
what date did the haiti earthquake happen
14 august 2021
what magnitude was the haiti 2021 earthquake
7.2
what type of plate boundqary did the earthquake occur
conservative
how deep was the focus+epicentre
10 km epicentre- 125km from capital port au prince
primary impacts of haiti 2021 earthquake
More than 2,000 people died and at least 12,000 were injured
Hospitals, schools and homes were destroyed.
secondary impacts
332 people were still missing five days after the earthquake
Hundreds of landslides took place, which destroyed local ecosystems and habitats
Heavy rainfall from Tropical Storm Grace turned the landslides into mud and led to widespread flooding
A 3 m high tsunami was recorded around the capital, Port-au-Prince.
responses
The United Nations and charities, such as the Red Cross and CAFOD, sent aid. However, the delivery of essential supplies was hampered by heavy rains from Tropical Storm Grace.
Temporary shelters were provided by the International Organization for Migration. These helped people who had lost their homes.
The World Food Programme increased their provision of hot meals for school children. This helped to deal with food shortages.
Temporary hospitals were constructed to help the injured. They also provided routine care, for example, some pregnant women gave birth safely within the temporary facilities.
The estimated cost of damages from the earthquake is around US$1.6 billion. This amounts to 9.6 per cent of Haiti’s GDP.
what is a prediction method used to predict earthquakes
seisometer
protection methods used during earthquakes
hazard proof buildings - Any new building or adjustment to existing buildings must be carried out to strict guidelines to help protect people from future earthquake hazards.
rubber shock absorbers to absorb earths tremors
steel frames - sway instead of collapse
open areas outside of the buildings where people can assemble during an evacuation
Lightweight roofs designed to reduce damage and injury
also drills and practise in schools and hospitals to know what to do in the event of an earthquake
what plate boundary causes tsunamis
destructive - oceanix plate subducts under continetal
what is the main effect of tsunamis
coastal flooding
The force of such large waves can also destroy coastal property.
