Term
| What are drowned river valleys and how do they form? |
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Definition
| Coastel inlet formed by partial submergence of a glacier |
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Term
| What are fjords and how do they form? |
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Definition
| Fjords need a) valley glaciers (high altitude) b) Mountains C)Coastal settings. U shaped, made by glaciers moving. |
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Term
| What are end moraines and outwash plains and how do they relate to cape cod and the islands? |
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Definition
End morains are ridges of solidated debrit deposited at the snout or end of the glacier.
Outwash plains are formed from melted silt and sediment from glaciers. Cape Cod has both of these. |
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Term
| How do the erosional effects of continental glaciers differ from valley glaciers? |
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Definition
| Continental glaciers strip away sediment cover - loose sediment. Valley Glaciers deepin the valleys - bigger sediment. |
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Term
| Why is the coast of maine rockey with numerous islands but few becahes |
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Definition
| Valley glaciers took away sediment. |
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Term
| Where do barriers occur along the sediment-starved coast of Maine? |
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Definition
| Sediment comes out of rivers, form barrier islands. Poppem, Algonquit, Welles, Old orchard beach. |
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Term
| Wbat are drumlins and what influence do they have on the Boston area? |
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Definition
| Accumilation of glaical sidemint injected into the till. With water creates ripples, raises land. Boston - Bunker Hill, Beacon Hill, Islands. |
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Term
| What does till consist of? |
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Definition
| Anything that can be picked up by glaciers - gravel, silt, mud, clay, boulders. |
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Term
| Why are the compositions of till and outwash sediment so different? |
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Definition
| Till is large and in the ice as outwash sediment is smaller - silt and mud and creates outwash plains. |
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Term
| What is a kettle and how do they form? |
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Definition
| Kettle is a pond. Ice blocks left behind in outwash plains. The ice melts and forms with the water underneath. Filled with sediment. |
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Term
| What are the Milankovitch Cycles and how do they relate to glaciation? |
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Definition
| Perturbations of the Earth's orbit around 3 sun. 3 Types Eccentricity, Obliquity and Precession |
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Term
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Definition
| 96,000 Year cycle. Changin earth's orbit from circular to ellyptical. Changes the distance to the sun. Less glaciation when circular more when ellyptical. |
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Term
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Definition
| 41,000 Year Cycle. Tilt of the Earth's Axis of Rotation from Vertical. Varies 21.8 to 24.4 affects seasonality. Greater the tilt, greater severity of seasons. |
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Term
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Definition
| 23,000 year cycle. Chnanges axis of rotation (tilted left or right - wobble). Changes Northern/Southern hemisphere seasons - switch. Now points to Norths Star - Will point to Vega. |
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Term
| Why does New England have stone walls? |
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Definition
| Glaciers stopped on outwash plains - leave good soil for farmers. Moved stones left by glaciers to the outside. |
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Term
| What dominant process do waves control along a beach and at a tidal inlet? |
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Definition
| 1) Long shore currents - transports sand along beach shore and to underwater beaches. 2) Barrier Island Formation. 3) Tidal Inlet formation. 4) Type of Backbarrier Setting. 4) Extent of tidal flats and marshes. |
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Term
| What dominant process do tides control along coastlines? |
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Definition
| Tides control spit system - ebb and flood currents. Another tidal inlet current can be connected. DIAGRAM. |
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Term
| How are tidal currents produced? |
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Definition
| Produced due to contriction of tidal waves coming into a bay, tidal inlet or funnel shaped embayement. Ex Bay of Fundy |
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Term
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Definition
| Draw, should have High tide, low tide, nodal point, tidal range, low slack water, high slack water, bay a, ocean b, time 1-4 (in order from top to bottom 3,2,4,1), flooding tide goes left, ebbing tide goes right |
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Term
| What factors affect wave energy along the coast? |
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Definition
Width of continental shelf
Storm Type and Frequency
Prevailing winds (west winds blow on shore - larger waves, more sediment transport) |
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Term
| Why are stomr waves important and why are they much more important in terms of sediment transport compared to average wave conditions? |
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Definition
| Storm waves larger so they can carry it longer, 25x stronger. 10 ft waves = 100 Energy. |
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Term
| What four shelf and ocean basinal characteristics influence coastal tidal ranges? |
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Definition
Shelf Width
Coastline configuration (bays or inlets)
How close you are to the nodal point (cross in bathtub)
How large tidal basin is |
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Term
| What is the tidal range in Boston Harber? If you didn't know what it was, how could you determine it? |
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Definition
| 10 ft/3 meters. Make a line from a high water mark, same with low and measure the difference between them. |
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Term
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Definition
| Volume of water that goes into an inlet, greater tidal prism means more inlets. |
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Term
| How could you determine the tidal prism of Boston Harbor? |
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Definition
| Determine water area multiply by tidal range |
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Term
| Wave Dominated Shorelines |
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Definition
| Micro tidal (waves under 2 meters). Long Linear barrier Islands. Few Tidal Inlets. Weel developed FTD, Poor ETD. Barriers backed by bays and lagoons. Marshes fringe mainland and barriers. Washovers Common. EX, Texas, Florida, Mississippi, New England, South Baltic Mediterranean. |
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Term
| Wave Dominated Shorelines - Diagram |
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Definition
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Term
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Definition
| Mesotidal (2-4 meter waves). River deltas poorly developed. Barrier islands short/stubbier. More tidal inlets. Flood and Ebb tidal deltas are well formed. Marshes and tidal flats abundant. Tidal creek systems - feed out of marshes. Ex: South Jersey, South Carolina, Gulf of Alaska |
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Term
| Mixed Energy Shorelines Diagram |
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Definition
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Term
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Definition
| No Barriers, Riverine sand is transported into linear sand shoals, large tidal ranges. Funnel shaped embayments. Onshore is tidal flats and expansive marshes. Ex: Bay of Fundy, Gulf of California, Bay of Bengal, Persian Gulf. |
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Term
| Tide dominated coasts Diagram |
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Definition
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Term
| What is the backbarrier and what different types of backbarrier settings exist along barrier coasts? |
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Definition
| Bay, Lagoon or Marsh. Backbarrier is between land and tidal inlet. |
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Term
| Why do wave dominate barrier coasts have lagoons and bays, whereas the backbarrier of mixed energy coasts consist of marsh and tidal creeks? (2 reasons) |
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Definition
| 1) Increase in tidal prism, increase # of tidal lets. More holes to let water in also sediment. 2) More exposure of tidal currents mean less marshes - waves won't let marshes form |
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Term
| Where does sand accumulaiate that eneters funnel shaped, macor tidal environments via rivers? |
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Definition
| Onto linear sand ridges which parallel tidal currents - shoals |
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Term
| Why do mixed energy coasts have more todal inlets and better developed ebb-tidal deltas than wave-dominated coasts? |
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Definition
| They have a greater mean wave height than wave dominated and higher mean tidal range than tide dominated |
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Term
| How and when do flood-tidal deltas form? |
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Definition
| When water comes into an inlet brings more sediment - creates like a sand bar |
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Term
| What are washovers, and whend and how do they from? What happens to washovers? |
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Definition
| Occur during storms, surges create enough force to push over the barrier. Cannabalistic process that allows barrier to move on shore and keep up with rising sea levels. Causes vegatation/marshes. |
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Term
| Why don't spit systems build across bays along a coast |
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Definition
| Spit's can't go across embayments because tidal currents don't allow them too. Spit constricts bay currents |
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