Earth Flashcards
What is the mean diameter of Earth in km
12,742km
What is the axial tilt of earth
23.5 degrees
What is the Earth’s Inner Core made out of
(is it solid or liquid)
solid iron-nickel (mostly iron) alloy, with an average temperature of 5,500C
It’s solid because of the pressure.
What is Earth’s Outer Core made of
What is special about the outer core
Liquid Iron, with some nickel
about 5,000C
Currents in the outer core are thought to create the earth;s magnetic field
What is the largest of earth’s layers, is it solid or liquid
The Mantle
Its solid but deformable, allowing convection currents on geological timescales
How thick is Oceanic Crust? (km)
How thick is Continental Crust? (km)
7-8km (oceanic)
25-70km (continental)
What is the mass of the earth in kilos (3 decimal places)
5.972 x 1024
What are the five layers of earth’s atmosphere, beginning at the lowest
Roughly what km range do they fill
Troposphere (0-16km at equator)
Stratosphere (16-56km)
Mesosphere (56-86km)
Thermosphere (86-700km)
Exosphere (>700km)
What is the name of the line that is often used to define the boundary between the atmosphere and outerspace (obviously there is no real boundary)
What is the altitude of this line in miles and kilometers
For kudos, what percentage is it of Earth’s radius
At what altitude do atmospheric effects become noticeable during re-entry
Karman Line
100km (62 miles)
1.57%
120km (75 miles)
What is the name for the study of Earth’s atmosphere and processes called [specifically what ‘ology’ is it]
atmospheric science
or aerology
What is the third most common element in the atmosphere?
What are the two most common molecules (not including water vapour)
Argon
CO2 and CH4
What is the altitude range of the International Space Station
What atmospheric layer is it in?
330-410km
Thermosphere
In what atmospheric layer do most meteorites burn up during reentry
What is the significance of this layer transport wise
Mesophere
Its too low for orbital or suborbital spacecraft but too high for jet aircraft
What atmospheric layer has the ozone layer
what does this mean for the definition of the layer
The stratosphere
The stratosphere defines a layer in which temperatures rise with increasing altitude.
This rise in temperature is caused by the absorption of ultraviolet radiation (UV) radiation from the Sun by the ozone layer, which restricts turbulence and mixing.
What is the name for the component of the atmosphere ionised by solar radiation
What famous thing happens in this area
The zone changes from day to night, but how far does it extend in day time
Ionisphere
auroras
50km to 1000km
Why is the sky blue during day and red at sunset
When light passes through our atmosphere, photons interact with it through scattering. If the light does not interact with the atmosphere, it is called direct radiation and is what you see if you were to look directly at the Sun. Indirect radiation is light that has been scattered in the atmosphere. For example, on an overcast day when you cannot see your shadow there is no direct radiation reaching you, it has all been scattered. As another example, due to a phenomenon called Rayleigh scattering, shorter (blue) wavelengths scatter more easily than longer (red) wavelengths. This is why the sky looks blue; you are seeing scattered blue light. This is also why sunsets are red. Because the Sun is close to the horizon, the Sun’s rays pass through more atmosphere than normal to reach your eye. Much of the blue light has been scattered out, leaving the red light in a sunset.
What is the difference between a siderial day and solar day
Why is the siderial day on earth four minutes shorter than the solar day (-best way of approaching it, is actually to ask why is the solar day four days longer)
Sideral day is a rotation relative to the stars (how long does it take a constellation to make a complete ‘orbit’)
The solar day is the same except with respect to the Sun (how long from noon-noon etc)
The sideral day is 23 solar hours and 56 solar minutes
The solar day is longer because of the orbit. It if revolved just a sidereal day amount the sun would have moved relatively so it needs to go a bit further to make the solar day. Remember the video?
What are the three atmospheric cells in the each of earth’s hemisphere’s starting at the equator going north
What is the name of the current that equalises the pressure between the cells
Hadley Cells
‘subtropical jet stream’
Ferrer Cells
‘polar jet stream’
Polar Cells
What are the trade winds
what do they mean for storms
The equatorially travelling descending air of the Hadley cells
In meteorology, the trade winds act as the steering flow for tropical storms that form over the Atlantic, Pacific, and southern Indian Oceans and make landfall in North America, Southeast Asia, and Madagascar and eastern Africa, respectively.
What is the middle latitude equivalent of the trade winds
the Westerlies
At what altitude (zone, as opposed to km) does the jetstream flow
Which way do they flow
near the altitude of the tropopause (which is the ceiling of the tropospheric cells)
West to east
What are Rossby waves (macroscopically)
and where are they most familiar
Also known as planetary waves, are a natural phenomena in the atmosphere and oceans that largely owe their properties to Earth’s rotation. (they are due to the variation in the Coriolis effect with latitude.)
Atmospheric Rossby waves are giant meanders in high-altitude winds with major influence on weather. These Rossby waves are associated with pressure systems and the jet stream
What is the ENSO?
What is the name of the warm phase,
What is the name of the cold phase
El Niño Southern Oscillation
It refers to the cycle of warm and cold temperatures, as measured by sea surface temperature, SST, of the tropical central and eastern Pacific Ocean.
The warm phase is called El Niño
The cold phase is called “La Niña”
The ENSO cycle, both El Niño and La Niña, causes global changes of both temperatures and rainfall.
Why are there different names for earths inner structures
Because it can be defined chemically or mechanically
What is the name of the mechanically rigid component of the Earth’s structure, and which components does it consist of
Lithosphere
consists of the crust and the upper portion of the mantle
What is the name for the upper most part of the lithosphere that chemically reacts to the atmosphere, hydrosphere and biosphere through the soil forming process?
Pedosphere
What is the asthenosphere
The asthenosphere (from Greek ἀσθενής asthenḗs ‘weak’ + sphere) is the highly viscous, mechanically weak and ductilely deforming region of the upper mantle of the Earth.
It is involved in plate tectonic movement and isostatic adjustments.
What is the name for the boundary between the earth’s crust and mantle (NOT lithosphere and asthenosphere)
What defines it
Mohorovičić discontinuity
The boundary is defined by a contrast in seismic velocity.
What are the three most abundant elements in the Earth’s crust
Oxygen (46.6%)
Silicon (27.7%)
Aluminum (8.1%) - the most abundant unambiguously metal
What is the name for the lower layer of the Earth’s crust
What minerals is it rich in
(and how does this relate to its name)
In what form does it come to the surface
and what else is it somtimes called
Sima (aka basal layer)
Magnesium Silicate (not name of Sima relates to these)
Comes the surface as Basalt, and since the ocean floors are therefore made of Sima is its sometimes called the oceanic crust
What is the name that refers to the composition of the upper part the Earth’s crust, and which is sometimes therefore equated with the continental crust
How does it get its name
How to geologists often refer to rocks in this area
Sial
named after rocks rich in silicates and aluminium minerals
It is however a geochemical term not a plate tectonic term
Geologists often refer to the rocks in this layer as felsic, because they contain high levels of feldspar, an aluminium silicate mineral series. However, the sial actually has quite a diversity of rock types, including large amounts of basaltic rocks.
What are p-waves and s-waves
Which ones are able to pass through liquids such as molten rock
p-waves are compression waves (these are the ones that can travel through liquids and molton solids)
S-waves (aka shear waves) shake rock from side to side and up and down so only travel through solid rock
Therefore P-waves can through the whole planet, but S-waves are prevent from doing that by the outer core (you can see how this can be used to determine the size of the core)
Who was responsible for the theory of continental drift (the precursor of plate tectonics)
How many major plates make up 94% of the earth’s surface
What plate does the UK sit on
Alfred Wegener (1880-1930)
7
then there are about a dozen smaller plates making up the rest
Eurasian plate
