natural hazards Flashcards
using figure 1 (a map showing plater margins and active volcanoes) which one of the following statements is true?
A) all active volcanoes occur in lines along plate margins
B) there are more active volcanoes along constructive margins than destructive margins
C) there are many active volcanoes around the edge of the pacific ocean
D) active volcanoes are found along the eastern side of north and south america
C - there are many active volcanoes around the edge of the pacific ocean
using figure 1 (a map showing plater margins and active volcanoes)
describe the movement of plates along plate margin X
one plate is subducted under the other
figure 2, a map of iceland showing tectonic plates
using figure 2 how long will it take for the plates to move 100 meters
A) 80 years
B) 250 years
C) 1200 years
D) 4000 years
D - 4000 years
using figure 2, a map of iceland showing tectonic plates, and your own understanding, suggest how plate movements cause tectonic hazards in iceland (6 marks)
in figure 2 iceland is shown to be on a plate margin. as a result, the movement of plates and subduction is caused by convection currents and consequently leads to the formation of earthquakes and volcanoes. the earthquakes formed in iceland are formed by plates moving apart at this margin. faults are formed at the margin so earthquakes can occur here. they are usually of low magnitude although some can be high magnitude as stated in the source. most happen at shallow depths below the surface where plates are moving apart. in addition, volcanic eruptions and activity occur at margins when two plates move apart. magma rises through the crust and some can erupt producing volcanoes. as a result of volcanic activity huge amounts of volcanic ash can pollute air, and glacial floods can be caused by heat. earth tremors and quakes can cause sudden movement of land.
figure 3, a graph showing variation in average global temperatures, 1880-2017
using figure 3 which is true?
A) in the early 1940’s global temperatures were below the 20th century
B) global temperatures saw a steady increase between 1940 and 1980
C) the 15 hottest years were all recorded between 1995 and 2017
D) global temperatures have been above the 20th century average every year since 1960
C - the 15 hottest years were all recorded between 1995 and 2017
give one natural cause of changes in global temperatures
changes in volcanic activity
give two pieces of evidence, other than the change in global temperature, that show climate change has taken place
extreme weather events, rising sea levels
which of the following statements about tropical storms is true?
A) tropical storms gain energy as they reach land
B) tropical storms develop along the equator
C) tropical storms occur in areas of high pressure
D) tropical storms form above oceans where temperatures are over 27 degrees
D) tropical storms form above oceans where temperatures are over 27 degrees
figure 3, info about cyclone idai and its impacts on mozambique
suggest why some tropical storms have severe primary and secondary effects using figure 3 and your own understanding (6)
first the type and magnitude affects the severity of the effects as some hazards risk is greater than other and if it is a higher magnitude it will have greater effects like Typhoon Haiyan was a category 5 quake which destroyed 90% of the city of tacloban. as well as this if there are more people in an area affected then the primary effects such as death rate will be higher because there is a greater probability they will be affected. worsened primary effects such as blocked roads may also lead to worse secondary effects like emergency services not being able to get to people. this may be because the country isn’t equipped to cope as the better a country a cope, the lower the risk of them being severely affected. being able to cope better means the risk of secondary effects like a weakened economy or supply shortages are reduced.
explain how the risks of a tectonic hazard can be reduced (4)
protection against earthquakes can be provided by buildings using reinforced concrete to absorb earthquakes energy therefore the impacts may be reduced to urbanised areas. existing buildings can be strengthened using steel frames therefore meaning less money will be needed to spent on repairing damage. it may also save lives as less rubble will block roads. buildings can also be strengthened in volcanic areas so they are less likely to collapse under weight of ash. planning can also reduce the risk by future development avoiding high risk areas. as well as this education and evacuation routes this means peoples know what to do and escape therefore decreasing the primary effects
state one source of evidence for long term climate change during the quaternary period
global temperature shifted between cold glacial periods and warmer interglacial periods
figure 6, photos showing strategies used to manage climate change (mitigation - alternative energy, carbon capture, adaption - adjusting to rising sea levels, growing drought resistant crops)
‘managing climate change involves both reducing causes (mitigation) and responding to change (adaption)’
do you agree? explain your answer using figure 6 and own understanding
i think that mitigation is more important than adaptation as it can reduce the amount of adaption needed to occur. firstly, alternative renewable energy replacing fossil fuels means less CO2 is being released into the atmosphere so it reduces the effects overall so there is no need to adapt to the effects. carbon capturing also means less emissions are released from power stations. planting trees is also a method of mitigation as it increases the amount of CO2 absorbed from atmosphere through photosynthesis. on the other hand adaptation in the form of better flood defences and people who cant afford defences building raised shelters as a way of coping with rising sea levels may be a good short term solution. as well as this drought resistant crops means new crop types are more suited to new climates and biotechnology means new crop varieties which are more resistant to extreme weather events reduces the risk of food shortages in the event of a natural hazard.
overall, whilst adaption is a good short term solution i think mitigation is a better sustainable long term method, however both are important to managing climate change
explain how the increasing use of fossil fuels and changes in agriculture may have contributed to global changes in temperature (4)
Fossil fuels account for over 50% of global greenhouse gas emissions. Burning these releases carbon dioxide into the atmosphere. Fossil fuels are used in transportation, building, heating homes, manufacturing industry, and generating electricity. Producing food uses fossil fuels in the production of fertiliser and pesticides, and in transporting. Changing forest cover to farmland also releases greenhouses gases. Increases in meat, dairy and rice production create more methane.
figure 4, map showing track of hurricane irma in september 2017
using figure 4 describe the track of hurricane irma between 6 september 2017 and 12 september 2017
its movement was in a North West direction and it passed to the north of Puerto Rico
figure 4, map showing track of hurricane irma in september 2017
what happened to the wind speed of hurricane irma between 8 and 12 september 2017
the wind speed reduced
give one reason why the wind speed of a tropical storm (hurricane) may change as it reaches land
slower movement due to winds in contact with land
