Prüfung Flashcards
Which rock types are the bright areas on the moon and how did they form?
Granite, plutonite, light colour because of minerals, lower cyrstallisation temperatur
What happens when continents collide?
Continental collision is a phenomenon of the plate tectonics of the earth that occurs at convergent boundaries. Continental collision is a variation on the fundamental process of subduction
Subduction zone destroyed
mountains produced
continents nurtured together
Name 4 official timeunits which are still ongoing today
- Phanerozoikum,
- Känozoikum,
- Quartär,
- Holozän
name 2 energy sources inside the Earth
- Primoridal heat,
- Gravitational energy (+ Radioactive Decay In The Mantle)
Name 3-4 official timeperiods which are in the past (- today)
- Kreide,
- Jura,
- Trias,
- Pilozän,
- Eozönm,
- Mesozoikum,
- Paläozoikum
Convection inside the earth: which type of energy is convection?
Energy that moves, it rises hot air masses from bottom to the surface of earth
5 structure types of silicate minerals
- isolated tetrahedra,
- chain of tetrahedra,
- double chain of tetrahedra,
- sheet of tetrahedra,
- complex three-dimensional network.
Definition of the magnitude on the richter scale?
Max. amplitude of the first seismic wave in 100 km distance from the epicentre. The scale logarithmic, meaning that each increase of one unit means a ten-fold amplification of the quake. Therefore large increase in damage only a few tenths increase in magnitude can occur.
Direct and indirect dangers of volcanoes?
direct: air fall, pyroclastic flow, CO2 lakes, lava flow
indirect: lahars, tsunamis, earthquakes, landslides
Direct and indirect dangers of earth quakes?
Direct: Groundmotion, Dislocation of the surface topography
Indirect: Fire, Liquefaction, Tsunamis, Landslides
What is the main source of heat on the surface of earth?
The sun
Which are the two main sources of heat on Earth?
Exogenous source: the sun.
Endogenous source: interior of the earth:
primordial heat – a leftover from the formation of the earth and its core.
gravitational contraction causes the Earth to decrease in volume and become denser, increasing the temperature in the process.
radioactive decay of isotopes in mantle and crust releases thermal energy.
What are 2 reasons for different density in the ocean?
- Salinity
- temperature
Name and describe 4 stages of the formation and development on earth
1) solar fog: accumulation of particles through gravitation, heat increase and rising gravity. Result: primitive Earth.
2) formation of core and mantle: heavy elements move to the centre, metals sink, silicates rise. Result: differentiated Earth.
3) mantle-crust-fractionation: basaltic magma formed through partial melting of primitive mantle. Result: developed Earth.
4) inter-crustal-differentiation: partial melting of lower crust, granitic melts rise into upper crust.
Result: modern Earth
Name and describe the three basic types of rocks.
igneous rock: formed from magma cooling slowly in the interior of the earth; due to the slow cooling, a crystalline structure can develop (intrusive igneous rocks). If magma cools rapidly,
volcanic rock (extrusive igneous rock) is formed – due to the fast cooling process, less or no crystals can form (like basalt).
metamorphic rock: formed through the change of igneous or sedimentary rocks due to pressure or temperature.
sedimentary rock: formed through the solidification of sediments; can be formed from organic remains (limestone) or from the cementing of other rocks
Which factor determines the type of soil that forms in a certain region?
Soil types depend on the original rock they form from/on; thereby rocks influence the agricultural or sylvicultural use of a region. limestone – rendzina sandstone – podzona loess – chernozem gneiss/shale – brown earth
Name five differences between basalt and granite
Basalt: Volcanite 50% quarzpart High density High Temp- Dark
Granite: plutonite 70% quarzpart low density low Temp light
Which process creates the magnetic field of the Earth? How can the magnetic field be used to reconstruct the formation of the ocean floor?
The convection current in the outer core causes the magnetic field. This magnetic field reverses from time to time, which offers the opportunity to date ocean floor. Certain atoms (for example atoms of magnetite) will face the direction of the magnetic north pole during rock formation and will stay in this position after the rock cooled down. Thereby a symmetric pattern on both sides of an MOR is created. With a lot of data and comparisons, this pattern can be used to date the material of the ocean floor.
Name the energy transport from the inner Earth to the Litosphere?
Convection
Name the energy transport from the inner Earth to surface?
Conduction
What is the normal geothermic gradient?
3 °C / 100 meters
Which mineral is basaltic magma and hydrolythic magma?
Basaltic: Olivine, Gabbro, Periodit
Hydrolythic: Granit, Quarz
Which two factors influence the sea-level?
eustatic oscillations: internal changes (in the ocean)
variation of surrounding land masses: subsidence, uplift, artificial removal of ground water, etc
Which factors influence the density of sea water and which three zones are
distinguished in the ocean?
Salinity and temperature define the density of the water.
Zones: − surface layer − thermocline, halocline, pycnocline − deep zone
Which two main processes induce deep water masses formation inside of recent oceans?
- Organisms like planktons create sediments,
- material from slopes slides to the oceans
What is the main rock type of the oceanic crust?
Basalt
How does heat flow in the inside of the earth?
Convection currents (heat transport through movements) in the plastic parts of the geosphere (outer core, mantle, asthenosphere) transport heat from the core towards the surface. Convection inside the mantle is one of three driving forces causing tectonic movement and it causes the magnetic field of Earth. In the solid parts (lithosphere, crust) conduction (heat transport without movement) takes place.
What is the reason for heat transport inside the earth?
Convection