Topic 1 (Not finished) Flashcards
What is the focus of an earthquake?
The focus of an earthquake is the point in the Earth where it starts
What is the epicentre of an earthquake?
The epicentre of an earthquake is the point on the Earth surface straight above the focus
What is the air circulation like in arid areas?
Sinking air from Hadley and Ferrel cells meets causes high pressure and prevents rainfall
What are the two types of volcano and where do they occur?
Composite volcanoes occur at convergent plate boundaries, shield volcanoes occur at hotspots or diverging plate boundaries
What is the structure of a composite volcano like and why?
Composite volcanoes have thick lava which can’t flow far forming a steep-sided cone. Their eruptions start with ash explosions which deposit layers of ash forming aha-lava-ash-lava layered structure
What is the lava of composite volcanoes like?
Composite volcanoes erupt andesitic lava, which has a high silica content making it thick and sticky
What path do tropical cyclones travel along and why?
Tropical cyclones move towards the west because of the easterly winds near the equator the Paths may start to curve further from the Equator as they get caught in the mid latitude westerlies
What has happened during the Quaternary period?
Global temperature has shifted between cold glacial periods of about 100 000 years and warmer interglacial periods lasting around 10 000 years
Why do deep focus earthquakes do less damage and shallow focus earthquakes?
Shockwaves from deeper earthquakes have to travel for more rock to reach the surface, reducing the power once they reach the surface
How did cyclone Nargis impact the environment of Myanmar?
The irrawaddy Delta in Lionel was the hardest hit area, a large proportion of it is only just above sea level and 14000 kilometres squared of land was flooded 38000 hectares of mangrove forests were destroyed
What is the temperature range in the Earth’s core
4400 to 6000 degrees Celsius
How can tropical cyclones be forecasted
Monitoring using satellites then using computer models to predict paths, measuring winds peed to monitor magnitude
Why is Arctic sea ice declining?
Because sea ice forms around the poles in winter when ocean temperatures fall below -1.8 degrees Celsius and melts during the summer when it’s warmer
Why do tropical cyclones cause landslides?
Heavy rain makes hills unstable causing landslides
How can volcanic activity lead to climate change?
Volcanic eruptions eject lots of material into the atmosphere. Some of the particles reflect the sun’s rays back into space so they don’t reach the Earth’s surface
How did Myanmar forecast for cyclone Nargis?
Myanmar doesn’t have a dedicated monitoring centre for tropical cyclones nor a radar network to predict the height of storm surges
Why does complexity cause uncertainty about future climate change?
There are lots of natural processes that we don’t fully understand
What happens at a conservative plate boundary?
Two plates are moving past each other in the same direction but different speeds or are moving sideways past each other
Why do emissions cause uncertainty about future climate change?
Predictions need to take into account things like population increase and economic development
How did hurricane Katrina impact People In The USA?
More than 1800 people were killed, 300000 homes were destroyed and hundreds of people were made homeless , 230000 jobs were lost from damaged business
Why is there no rain at 30 ° s/n of the equator?
As cool air sinks there creating a high pressure belt with cloudless skies and low rainfall
What are the four stages of cycling formation
Initial conditions, rising air plus clouds , rotation begins , maturity
What are the three types of plate boundary?
Convergent boundaries, divergant boundaries, Conservative boundaries
Why do earthquakes occur at divergent plate boundaries?
Tension builds up along cracks within plates as they move away from each other
What are some of the impacts on the environment of tropical cyclones?
- storm surges erode beaches - trees uprooted, habitats destroyed - landslides deposit sediment in lakes can kill fish
What happens during the rotation begins stage of a tropical cyclone.?
When’s moving upwards spiral as they converge to spin the storm. Coriolis effect causes a contents to Spiral around the centre of the storm spinning the storm.
Why is energy causing increased greenhouse effect?
- Co2 is released into atmosphere when fossil fuels burnt - Most energy produced this way - More Tech + People increases demnad
What are Tsunamis?
Tsunami are a series of enormous waves caused when huge amounts of water get displaced
Why might some countries have economic vulnerability to tropical cyclones
- agriculture dependance of people - people may not have insurance for repairs
Which countries usually have the most economic vulnerability to tropical cyclones?
Rich as more damage is done so more repairs needed
How are deep ocean currents crated?
When water freezes at the poles the surrounding water gets saltier, increasing in density. It sinks causing warmer water to flow in at the surface. The warmer water cools and sinks repeating the cycle
How can historical records be used for evidence for climate change?
Since 1850s global temperatures have been accurately measured with thermometers giving a reliable but short term record. Historical diaries dan say the harvest times, or when there was rain or snow to give an idea of the climate before.
What are the four pieces of evidence for human activity causing climate change?
Declining arctic ice, global temperature rise, extreme weather events, sea level rise and warming oceans
What may orbital changes have lead to?
Caused the glacial and interglacial cycles of the Quaternary period
Where are polar cells found?
.on either sides of the poles
What condition do tropical cyclones need to develop?
See temperatures above 26.5°C
How did hurricane Katrina impact the environment of the USA?
Flooding damaged oil refineries in Louisiana causing massive oil spills Some coastal conservation areas were destroyed are coastal habitats were damaged
What are some of the impacts on people of tropical cyclones?
- People may drown in string currents created - homelessness as buildings destroyed - easy disease spread as little sanitation - unemployment
How does farming cause climate change?
- Farming of livestock produces a lot of methane (farting cows) - Rice paddies contribute to global warming as flooded fields emit methane - Trees absorb and store CO2 but when land is cleared of them for farming it stops CO2 being absorbed leaving more co2 in the atmosphere
What is a storm surge
A storm surge is a large rise in sea level caused by low pressure and high winds
What is thermal expansion?
Water in the oceans expands as It Gets warmer this is called thermal expansion
What are surface winds blowing to the poles and equator called?
Poles - westerlies Equator - Trade Winds
What can be done to defend against tropical cyclones?
- Defences built along coasts to protect from damage from storm surges - Buildings designed to withstand storm surge, high winds etc
Why do volcanoes occur at hotspot?
Sometimes the magma can break through the crust and reach the surface, an eruption snd volcano forms
What is air flow like in tropical areas?
Rising air from two Hadley cells meets causes low pressure with lots of rainfall
What do orbital changes in the Earth’s orbit cause?
They affect the amount of solar radiation the Earth receives and where it is distributed.