GEOLOGY 101 EXAM 3 TAMU
Jetties - ANSWERS-Extend into the ocean at the entrances to rivers and harbors -
Usually built in pairs
-Jetties are built to aid shipping, to prevent sand deposition in a channel; the
confined flow of water prevents sand buildup
Groins - ANSWERS-Constructed at a right angle to the beach to
trap sand and widen beaches
Seawall - ANSWERS-Barrier built on shoreline to prevent landward retreat of
shoreline; usually changes shore from sand beach to rock-covered shore
What area is in highest risk of ocean flooding due to hurricane? - ANSWERS-Risk
of flooding by ocean water during hurricanes is greatest in south Florida and the
Gulf Coast
What is happening with most sand shorelines? - ANSWERS-ost sand shorelines are
eroding
- short term as sand moves and is re-arranged by waves - long term due to sea
level rise
Beach replenishment - ANSWERS-Rebuilding the shore by addition of large
quantities of sand to the beach system
,Development on the shore - ANSWERS-Development occurs mainly on barrier
islands Barrier islands face the open ocean
They receive the full force of storms
-Abandonment and relocation of buildings away from the beach is the only
permanent solution
Glaciers - ANSWERS-originate on land from the compaction, and recrystallization
of snow
-2 % of world's water is contained in glaciers Antarctic ice sheet
If melted, sea level will rise 60 to 70 meters
Cirque - ANSWERS-Ice accumulates at top of mountain and they move down
eroding the mountain creating these semi circle basins which is what a Cirque is.
Zone of accumulation - ANSWERS-area where a glacier forms
Zone of wastage - ANSWERS-the area where there is a net loss to the glacier due
to melting and calving
Calving - ANSWERS-the breaking off of large pieces of ice (icebergs where the
glacier has reached the sea)
, Glacial till - ANSWERS-material deposited directly by the glacier; Is unstratified
and unsorted
Glacial Moraine - ANSWERS-Moraines are accumulations of dirt and rocks that
have fallen onto the glacier surface or have been pushed along by the glacier as it
moves.
Esker - ANSWERS-Deposit of sediment formed by sub-glacial stream
flow of meltng glacier
Glacial caves: - ANSWERS-caverns made by streams in the base of glaciers that
drain meltwater moving along fractures in the ice.
-Rocks and sediment that accumulated in the cavern is exposed as an esker when
the ice melts.
Ice Ages (2.6 millions years to present) - ANSWERS-10-20 major advances of
continental glaciers in northern hemisphere
• Ice covered 30% of Earth's land area
• Occurred during a division of geologic time called the Pleistocene epoch
Ice Cores - ANSWERS-Ice cores are formed of annual layers of snowfall and can be
dated like tree rings. Have a half-million year record of climate.
-Air is entrapt and can tell what the atmosphere was like back then which was
dustier
Jetties - ANSWERS-Extend into the ocean at the entrances to rivers and harbors -
Usually built in pairs
-Jetties are built to aid shipping, to prevent sand deposition in a channel; the
confined flow of water prevents sand buildup
Groins - ANSWERS-Constructed at a right angle to the beach to
trap sand and widen beaches
Seawall - ANSWERS-Barrier built on shoreline to prevent landward retreat of
shoreline; usually changes shore from sand beach to rock-covered shore
What area is in highest risk of ocean flooding due to hurricane? - ANSWERS-Risk
of flooding by ocean water during hurricanes is greatest in south Florida and the
Gulf Coast
What is happening with most sand shorelines? - ANSWERS-ost sand shorelines are
eroding
- short term as sand moves and is re-arranged by waves - long term due to sea
level rise
Beach replenishment - ANSWERS-Rebuilding the shore by addition of large
quantities of sand to the beach system
,Development on the shore - ANSWERS-Development occurs mainly on barrier
islands Barrier islands face the open ocean
They receive the full force of storms
-Abandonment and relocation of buildings away from the beach is the only
permanent solution
Glaciers - ANSWERS-originate on land from the compaction, and recrystallization
of snow
-2 % of world's water is contained in glaciers Antarctic ice sheet
If melted, sea level will rise 60 to 70 meters
Cirque - ANSWERS-Ice accumulates at top of mountain and they move down
eroding the mountain creating these semi circle basins which is what a Cirque is.
Zone of accumulation - ANSWERS-area where a glacier forms
Zone of wastage - ANSWERS-the area where there is a net loss to the glacier due
to melting and calving
Calving - ANSWERS-the breaking off of large pieces of ice (icebergs where the
glacier has reached the sea)
, Glacial till - ANSWERS-material deposited directly by the glacier; Is unstratified
and unsorted
Glacial Moraine - ANSWERS-Moraines are accumulations of dirt and rocks that
have fallen onto the glacier surface or have been pushed along by the glacier as it
moves.
Esker - ANSWERS-Deposit of sediment formed by sub-glacial stream
flow of meltng glacier
Glacial caves: - ANSWERS-caverns made by streams in the base of glaciers that
drain meltwater moving along fractures in the ice.
-Rocks and sediment that accumulated in the cavern is exposed as an esker when
the ice melts.
Ice Ages (2.6 millions years to present) - ANSWERS-10-20 major advances of
continental glaciers in northern hemisphere
• Ice covered 30% of Earth's land area
• Occurred during a division of geologic time called the Pleistocene epoch
Ice Cores - ANSWERS-Ice cores are formed of annual layers of snowfall and can be
dated like tree rings. Have a half-million year record of climate.
-Air is entrapt and can tell what the atmosphere was like back then which was
dustier
