Earthquakes rock under stress o Stress applied push pull or shear o Strain reaction to stress Waves o P wave compressional waves fastest waves materials moves back and forth in direction of wave Pushing and pulling a spring o S wave shear waves moves 60 of p waves Materials move in up and down wave direction ONLY UP AND DOWN Surface waves travel ALONG surface slower cause more structural damage Like a sine wave but flat along the surface o Rayleigh R waves resembles ocean waves Moves up down and side side Circular motion and moves o Love L waves resembles a sideways s wave Fastest surface wave Hypocenter where it happens in the ground Epicenter where it happens on the surface Seismogram record vertical and horizontal ground motion Usually 3 seismographs at each location The three can be used to triangulate the location Using the Richter magnitude scale you measure the amplitude of the highest S wave and the distance The intersection of these two will give you magnitude The distance can be figured out by measuring the distance between the first P wave and the first S wave X amount of time equals x amount of distance Slip amount Plate tectonics Sampling earth s interior using different seismic waves to find the interior of earth Japanese tsunami Orogeny mountain building event processes that collectively produce a mountain belt Happens at convergent boundaries Range of mountain Uplift erosion Compression Squeezing Tends to thicken material Becomes longer Tension pull apart Thin material Become wider Shear blocks or rock sliding past one another Neither thickened or thinned Two types of deformation dependent on t p deformation rate composition o Brittle material breaks discontinuous Offset displacement slip point A and B are spread out the distance between start and end of split imagine a Y it s the length of the branch Fault scarp Drag folds when fault moves it causes small fold The motion is like a shear and the layers get messed up One end is like folded like a fishing hook and other is moved away Looks like Fault breccia gouge Slip lineation linear marks on fault plane caused by slip o Ductile material flows without breaks continuous Dip slip movement along fault plane dip always verticle Normal extension Hanging wall down happens from extension Reverse compression Hanging wall up happens from compression Thrust 35 degree Strike slip horizontal Move in opposite direction Oblique slip most common vertical and horizontal Moves at 45 degrees but downwards Joint natural cracks without movement Looks like tiles o Systematic regularly spaced long repeating o Nonsystematic random short o Vein mineral filled joint Folding o Anticline upward Hinge line is where it folds Limbs on side Creates dome o Syncline downward Creates basin Mountain belts continent continent collision india and asia Continental accretion when islands like Hawaii crash into another continent called terranes Mountain building associated with Rifts continental thinning pulls away and magma comes up and makes mountain but continues to move away and more magma comes up Isostasy concept of a floating crust in gravitational balance Appalachians they formed when the two crusts were moving together then started to diverge and spread out then they started to converge again diverge again converge diverge and finally converge Caused many mountains for to There were 4 orogeny events that took place New jersey they are roots of the Appalachians formed from differential erosion erosion occurs at varying rates caused by different resistance and hardness in rocks Principle of superposition oldest on bottom youngest on top Principle of original horizontality layers of sediment when originally deposited are fairly horizontal Principle of original continuity layers of sediment form fairly continuous sheets over a region layers in a canyon Principle of Cross cutting relations a geologic feature dike that cuts across another feature is younger than the feature that it cuts into Dike younger than what it cuts into Principle of inclusions if an igneous rocks contains rock fragments fragments are older than rock Principle of baked contacts rock that is baked is older than the intrusions Whatever pluton cuts into is the older one 3 types of unconformities o Angular unconformity sedimentary over folded tilted rock Compression top gets eroded new layers form at angle b c of compression o Nonconformity metamorphic have foliation direction or igneous large grain size no foliation rocks overlain by sedimentary strata o Disconformity unconformity between parallel layers of sedimentary rocks which represents period of erosion hiatus missing time due to erosion Radiometric dating age of mineral can be determined by measuring the amount of parent daughter isotopes using known half life Dinosaur extinction caused by large asteroid that caused debris in the air tsunamis shock wave that caused earthquakes and volcanoes Debris blocked sun got cold no photosynthesis Hydrocarbons hydrogen and carbon bonds Different amount of hydrogens attached Hydrocarbons come from source rock which contain algea plankton quiet low oxygen deposition temp pressure o Source rock algea plankton Low temp long time breaks the organics into waxy kerogen Organic rich mud turns to black shale under heat and press Kerogen forms As temp inc kerogen turns into oil and it rises o Reservoir rock can hold oil and rock usually sandston High porosity amt of open space in rock Permeability connectedness between pores o Trap rock no pores or permeability Peat 50 compaction garden fertilizer Lignite 70 compaction heated compressed Bituminous 45 85 heated compressed Anthracite 90 95 most efficient highly compacted Left Earthquake Seismology Seismic moment magnitude scale slip amount x rupture length x rupture depth x rock strength Plate tectonics Plate tectonic boundaries account for about 95 if all earthquakes Japanese Tsunami near east coast of honahu in 2011 magnitude of 9 0 sampling earth s interior Deformation Forces stress Pressure object feels the same stress on all sides o ex diver underwater Compression squeezing greater stress in 1 direction tends to thicken material ex squeezing from the sides but not the top and bottom o ex continental collision pushes from sides not from top and bottom Extension pull apart greater stress in 1 direction tends to thin material Pushes from top bottom making object thinner sides extend while top bottom goes down o ex continental rift pulls apart