Term
|
Definition
| has water table, is only partly filled with water |
|
|
Term
|
Definition
| completely filled with water has aquitard at top, which separates it from surface |
|
|
Term
| Drawdown and Cones of Depression |
|
Definition
| results when water is pumped faster than recharge can refill the region near the well |
|
|
Term
|
Definition
| the addition of new water to the saturated zone |
|
|
Term
|
Definition
| caves, speleothems, sinkholes, springs |
|
|
Term
|
Definition
| continental scale glaciation at high latitudes (polar regions) |
|
|
Term
|
Definition
| glaciation in mountainous regions (high elevations) |
|
|
Term
| Pleistocene Glacial Maximum |
|
Definition
| Maximum extent of glaciers--18,000 years ago |
|
|
Term
|
Definition
| occupy valleys in mountainous regions |
|
|
Term
|
Definition
| continental sized, can be kilometers thick |
|
|
Term
|
Definition
| SNOW becomes compacted into FIRN then eventually recrystallizes into GLACIAL ICE |
|
|
Term
|
Definition
| region in upper part of glacier where more snow accumulates than melts |
|
|
Term
|
Definition
| region in lower part of glacier where more snow/ice melts than accumulates |
|
|
Term
|
Definition
| the line between the zone of accumulation and the zone of ablation at the end of the--can usually be seen as the line separating white snow on the surface of the upper part of the glacier from darker snow/free ice in the lower part of the glacier |
|
|
Term
|
Definition
| If the equilibrium line advances down the valley it indicates a net gain in glacial ice and the glacier is advancing |
|
|
Term
|
Definition
| If the equilibrium line is moves up the valley, it indicates a net loss in glacial ice and the glacier is retreating |
|
|
Term
|
Definition
| meltwater often forms near the base of glaciers and can act as a lubricant to facilitate basal sliding |
|
|
Term
| Rigid Zone vs. Zone of Plastic Flow |
|
Definition
| the top part of glaciers deforms in a brittle fashion and is called the rigid zone. This part of the glacier mostly just goes along for the ride on top of the lower part of the glacier which due to the pressure of the overlying ice deforms in a plastic fashion (it flows) |
|
|
Term
|
Definition
| crevasses form in the rigid zone, where the ice is under tension such as on the outside of curves in the valley or where the glacier goes over convex topography |
|
|
Term
|
Definition
| glacial ice in continental ice sheets tends to be very thick, so plastic flow in the lower part of the ice sheet dominates. |
|
|
Term
|
Definition
| rock fragments trapped in ice at the base of the glacier that grind away at the bedrock beneath |
|
|
Term
| Polished and Striated Surfaces |
|
Definition
| direction of flow indicators--striations in bedrock can indicate the direction of previous glacial flow |
|
|
Term
|
Definition
| streams tend to cut v-shaped valleys, while glaciers tend to cut u-shaped valleys, with very steep walls and flat valley floors |
|
|
Term
|
Definition
| steep ridges separating valleys |
|
|
Term
|
Definition
| steep peaks carved out by headward erosion of cirques on three or more sides |
|
|
Term
|
Definition
| half-bowl shaped forms eroded out by the upper parts of glaciers and through mass wasting |
|
|
Term
|
Definition
| hanging valleys form where smaller glacial tributary valleys are not eroded to the same extent as the major glacial valleys, often producing waterfalls |
|
|
Term
|
Definition
| glacially deposited sediments that tend to be angular and very poorly sorted (glacial ice can carry everything from fine dust to house-sized boulders) |
|
|
Term
|
Definition
| form in the center of large glaciers where LATERAL moraines from the edges of tributary glaciers come together |
|
|
Term
|
Definition
| deposits of till at the terminus of the glacier--sub types are TERMINAL moraines that form at the end of the farthest extent of the glacier; and RECESSIONAL moraines that form as the glacier recedes |
|
|
Term
|
Definition
| mound-shaped deposits of till |
|
|
Term
|
Definition
| deposits of reworked till that form in tunnels carved under glaciers by meltwater |
|
|
Term
|
Definition
| lakes that form as large blocks of ice melt in till deposits in outwash plains |
|
|
Term
|
Definition
| streams that form from meltwater at the snouts of glaciers; tend to have heavy sediment loads and thus produce large numbers of gravel bars and large numbers of channels |
|
|
Term
|
Definition
| fine-grained wind blown deposits |
|
|
Term
|
Definition
| mark the extent of past glaciation |
|
|
Term
|
Definition
| ice sheets contributed to creation of the Great Lakes by widening existing stream valleys. The Finger Lakes of New York formed through glacial till deposits damming up glacial valleys. |
|
|
Term
|
Definition
| formed from wetter conditions in glacial ages |
|
|
Term
|
Definition
| drowned glacial valleys that formed as glaciers retreated and sea level rose |
|
|
Term
|
Definition
| lithified till deposits provide evidence of very old periods of glaciation |
|
|
Term
|
Definition
| vertical distance from trough (low part) to crest (high part) |
|
|
Term
|
Definition
| horizontal distance form crest to crest or trough to trough |
|
|
Term
|
Definition
| time for one wavelength to pass by a given point |
|
|
Term
|
Definition
| individual water particles move in near circular orbits as a wave passes by |
|
|
Term
|
Definition
| relationship to wavelength--particle motion diminishes with depth until it is gone at a depth of about 1/2 the wavelength |
|
|
Term
| Surf Zone relationship to Wave Base |
|
Definition
| once the water depth is less than the wave base, the wave starts to "feel" the sea floor. The interaction of the sea floor and the wave results in drag on the orbital water particles and slows the bottom of the waves |
|
|
Term
|
Definition
| the top of the wave continues to move more rapidly than the lower part and results in the wave toppling over or "breaking" |
|
|
Term
|
Definition
| waves coming in at an angle to the shoreline feel the drag effects of the sea floor at one "end" of the wave first causing part of the wave to slow down, while the part of the wave that is still in deeper water continues to move more rapidly--this causes the wave to bend or "refract" until it becomes closer to parallel to the shoreline. |
|
|
Term
|
Definition
| waves still coming in a small angle to the shore result in development of a current parallel to the shoreline known as a longshore current. Prevailing wind direction produces a longshore current with a prevailing direction. |
|
|
Term
|
Definition
| result from water piling up along shore due to longshore currents. Move seaward as narrow near surface currents in places of lower wave heights for incoming waves |
|
|
Term
|
Definition
| gently sloping landward part of beach |
|
|
Term
|
Definition
| steeply sloping part of beach in swash zone |
|
|
Term
|
Definition
| form as spits extend all the way across the mouths of bays |
|
|
Term
|
Definition
| sand deposits that form when longshore currents that move sand along the shoreline encounter deeper water in a bay and drop their sediment loads |
|
|
Term
|
Definition
| sand deposits that build up behind sea stacks (isolated islands near the coast) |
|
|
Term
| Jetties, Groins, and Breakwaters |
|
Definition
| man-made structures designed to keep channels open, interrupt longshore currents and stabilize beach sediments, and maintain quiet waters |
|
|
Term
|
Definition
| most beach sands sourced from rivers and reworked by longshore currents and wave action |
|
|
Term
|
Definition
| flat platforms cut by wave activity |
|
|
Term
|
Definition
| erosional remnants of headlands |
|
|
Term
|
Definition
| sea caves through eroded headlands that form arches |
|
|
Term
|
Definition
| islands that parallel coastlines with lagoons behind them |
|
|
Term
|
Definition
| flooded river valleys that formed as sea level rose |
|
|
Term
|
Definition
| flooded glacial valleys that formed as sea level rose |
|
|
Term
|
Definition
| form in regions of warm shallow clear water through growth of calcium carbonate producing organisms |
|
|
Term
|
Definition
| form from growth of reef systems around sinking volcanic islands |
|
|
Term
|
Definition
| plates squeezing together |
|
|
Term
|
Definition
|
|
Term
|
Definition
| plates shearing (sliding past) |
|
|
Term
|
Definition
| deformation that results from stress |
|
|
Term
|
Definition
| the maximum amount of stress that can be applied to a body before it deforms in a permanent way by bending or breaking |
|
|
Term
|
Definition
| non-permanent deformation rock returns to pre-stressed state once stress is removed. Rocks can only deform elastically until they reach their elastic limit. Once past this limit, deformation will be permanent. |
|
|
Term
|
Definition
| deformation involving breaking of the rock |
|
|
Term
|
Definition
| deformation in which the rock deforms plastically |
|
|
Term
|
Definition
| rapid strain rate tends to result in brittle deformation, slower strain rate results in ductile deformation |
|
|
Term
|
Definition
| strike is the azimuth of a horizontal line in a plane, dip is the inclination of the plane. Dip is measured at 90 degrees to strike. Together, strike and dip uniquely define the orientation of a planar surface such as a bedding layer or fault surface. |
|
|
Term
|
Definition
| maps showing geological formations and structural elements with strike and dip symbols to indicate the orientation of layers, faults, and folds. |
|
|
Term
|
Definition
| representations of vertical slices through the earth |
|
|
Term
|
Definition
| a theoretical line if moved parallel to itself will form the shape of the fold |
|
|
Term
|
Definition
| a planar surface containing the fold axis or hinge lines for each layer of the fold. |
|
|
Term
|
Definition
| the hinge is the point of maximum curvature of the fold; the limbs are the sides of the fold |
|
|
Term
|
Definition
| upward arching folds with older rocks near the core of the fold |
|
|
Term
|
Definition
| downward arching folds with younger rocks near the core of the fold |
|
|
Term
|
Definition
| circular up-warped (domes) or downwarped (basins) structures |
|
|
Term
|
Definition
| fractures across which there has been displacement (slip) |
|
|
Term
|
Definition
| slip is in the direction of dip |
|
|
Term
| Hanging Wall vs. Footwall |
|
Definition
| hanging wall refers to the block above the fault while footwall refers to the block below the fault plane |
|
|
Term
|
Definition
| faults where the hanging wall moves down relative to the footwall |
|
|
Term
|
Definition
| faults where the hanging wall moves up relative to the footwall |
|
|
Term
|
Definition
| low angle (shallow dipping) reverse faults |
|
|
Term
|
Definition
| slip is in the direction of strike (faults are near vertical); slip is mostly horizontal |
|
|
Term
| Right-Lateral vs. Left-Lateral |
|
Definition
| relative motion between blocks moves fault block on the opposite side of the fault either to the right or the left. |
|
|
Term
|
Definition
| components of both dip-slip and strike-slip motion |
|
|
Term
|
Definition
| point within the earth where rupture occurs. seismic waves originate from the focus |
|
|
Term
|
Definition
| point on Earth's surface directly above the focus |
|
|
Term
|
Definition
| travel through earths interior |
|
|
Term
| P Waves (primary, compressional) |
|
Definition
| fastest, arrive first at seismic stations, travel through solids and fluids. |
|
|
Term
| S Waves (secondary, shear) |
|
Definition
| slower, arrive second at seismic stations, only travel through solids. |
|
|
Term
|
Definition
| travel along Earth's surface away from the epicenter |
|
|
Term
|
Definition
|
|
Term
|
Definition
|
|
Term
|
Definition
| instruments that detect seismic waves |
|
|
Term
|
Definition
| paper or digital records of seismic waves |
|
|
Term
|
Definition
|
|
