Exam Revision Flashcards
What is the current accepted hypothesis for solar system formation?
The Nebula Hypothesis.
What is the age of the universe?
13.8 billion years old.
What is the regolith?
The earth’s layer of rock and mineral fragments produced by weathering.
What was the key stage in the development of oxygenic photosynthesis?
The functional linking of two photosystems in one organism.
Which element serves both as a key ion in cellular fluids and as a cofactor in biological molecules?
Magnesium.
What is the minimum sea-water temperature?
-2 degrees.
The current characterised by a balance between the Coriolis force and the foce exerted by the horizontal pressure gradient is called:
Geostrophic.
Which set of terms are all relevant to tsunamis?
Very long wave lengths, 100km/h
What is the earth’s magnetic field generated in?
The earth’s liquid metal alloy outer core.
At what temperature does seawater attain its highest density?
-2 degrees.
The industrial age increase in atmospheric CO2 levels concerned an amount of carbon roughly equivalent to:
1/3 the amount of carbon contained in the world’s current living biomass.
The Ekman spiral describes…?
The directional change in transport with depth in a wind-driven surface layer.
On a smooth non-rotating earth…?
We would expect 1 thermally direct circulation cell per hemisphere in the atmosphere.
Considering the global carbon budget over very long time scales, weathering of silicate rocks….
Withdraws CO2 from the atmosphere.
Which characterists do mid-latitude cyclones and hurricanes have in common?
Surface pressure lowest at centre.
What are the sub-atomic particles?
Hadrons containing baryons & mesons (composite particles) & elementary particles containing fermions (quarks and leptons) and bosons.
What is the frost line?
The line in a solar system beyond which water freezes.
What is the earth’s inner core made of?
A Nickel-iron mix.
What is the Earth’s mantle made of?
A stony (silicate) mantle.
What are the two types of meteorites?
Differentiated - Fe/Ni metal, representing already differentiated cores of proto-planets smashed in asteroid belt.
Undifferentiated - Chondrites, 86% of earth falls. Stony, silicate composition, close to sun. Primitive - suggests early formation.
What is the blocking or closure temperature?
The temperature below which daughter molecules can no longer diffuse out of the material e.g. crystallisation of lava.
What is the Lithosphere?
The outermost 100-150km of earth. Behaves rigidly. Comprised of crust and upper mantle.
What is the Asthenosphere?
The upper mantle below the lithosphere. Shallow under oceanic lithosphere, deeper under continental.
What is polar wandering?
The change in the positions of the countries in relation to the magnetic pole of the world.
What are the two types of lithosphere?
Continental (thicker) and oceanic (thinner)
What does oxygen determine in planet formation?
The size of the planet’s lithophile silicate layer.
What does sulphur determine in planet formation?
The size of the chalcophile layer.
What do excess metals determine in planet formation?
The size of the siderophile layer.
What are the silicates?
The rock-forming minerals. They constitute almost the entire crust & mantle of earth, & are the most common, e.g quartz.
What are the oxides?
Metal cations bonded to oxygen e.g. magnetite, hematite, rutile.
What are the sulfides?
Metal cations bonded to a sulfide anion, i.e. pyrite, galena and sphalerite.
What are the sulfates?
Metal cations bonded to a sulfate anionic group. E.g. gypsum, anhydrite, halides.
What is the Si:O ratio important for in silicate minerals?
Defining melting temperature, structure and cations present, and susceptibility to chem weathering.
What is continental crust made of?
Granite - less dense.
What is oceanic crust made of?
Basalt - more dense.
What is weathering?
The disintegration and decomposition of rocks and sediments by mechanical or chemical processes.
What is erosion?
The process by which particles primarily of rock or soil are detached by wind/water/ice.
What is physical/mechanical weathering?
Physical disintegration of a rock into smaller fragments. Usually by temp/pressure changes.
What is chemical weathering?
Alteration or change in composition of a mineral due to the action of chemical agents.
What is lithification?
Compaction through burial. Clastic sediments.
