| Term | Definition |
|---|
| Biosphere | thin layer of life on earth's surface |
| Ordovician Ocean | around 450 Milion yrs BP |
| Cretaceous Ocean | around 130 million yrs BP |
| Principle of Superposition | what's on top is youngest |
| Principle of Faunal Succession | strata of like age can be recognized by the fossils they contain |
| Biostratigraphy | using the appearance and disappearance of fossils to subdivide geological time |
| Characteristics of mass extinction | at least 30% of species lost, broad range of ecologies, short/sudden |
| 5 extinctions in Phanerozoic | cretaceous/tertiary, end triassic, permo/triassic, late devonian, late ordovician |
| causes of mass extinctions | biological, earth based, atmospheric, extraterrestrial, combination |
| Cretaceous/Tertiary Extinction | dinosaur killer, at least 50% species lost |
| The Crater: "the smoking gun" | crater 180 km across off coast of Mexico, Chicxulub, asteroid 10 km across |
| Oort Cloud | comet store dirty snowballs, commonly around 15km diameter |
| Torino Scale | 0-10, assess risk of NEO |
| Proposed Mitigation Strategies | fragmentation, sudden orbit adjustment, steady state orbit adjustment, ablation system, ridind solar winds |
| 3 types stresses | compression, tension, transverse |
| fault | large brittle fracture in a rock body, point of origin for most earthquakes, m-km |
| fractures | usually mm-cm |
| Reverse fault | caused by compression, block moves towards each other, hanging block moves upwards relative to footwall |
| Normal Fault | caused by tension, blocks move away, hanging wall block moves down relative to footwall |
| Hypocentre | (focus) where motion begins on the fault |
| Epicentre | directly above the hypocentre on the surface |
| Elastic Rebound Theory | how earthquakes build energy |
| Body Waves | P and S waves, move within the Earth, much faster than surface waves, not damaging to buildings |
| P waves | primary or pressure, fastest, travel through solids or fluids, arrive first (accordian) |
| S waves | secondary or shear, travel through solids only (slink) |
| Surface waves | vertical and horizontal waves, move at the surface, much slower than body waves, cause more damage (rayleigh, love) |
| Rayleigh Waves | up and down |
| Love Waves | side to side |
| Richter Scale | no longer in use, quantative scale, measures amplitude |
| Moment Magnitude Scale | measures strain energy along rupture surface, logarithmic, each # 32x more energy releas and 10x more shaking |
| Foundation material | bedrock = more intense, well compacted sediment = less intense |
| Earthquake hazards | ground shaking/ ground rupture, liquefaction, fire, tsunami, ground failure/landslide |
| Modified Mercali Scale | qualitative measurement, what we feel, 1-12 |
| divergent boundaries | smaller earthquakes, associated with volcanoes |
| convergent boundaries | small to very large earthquakes, subduction zones are where largest volcanoes occur |
| tektites | produced by melting rocks during impact |
Combine with other sets
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