Glacial Landscapes Flashcards

Question

Glacial Troughs

Answer 1

A u-shaped valley formed by a glacier bulldozing and eroding through a river valley The glacier has enough force to erode a rivers interlocking spurs leaving smooth but steep truncated spurs aswell as a wide flat valley floor The original river will continue to flow but now as a misfit stream due to the difference in its size with its surroundings

Answer 2

A smaller u-shaped valley caused by a tributary glacier. The smaller glacier does not have enough energy to erode to the valley floor leaving a hanging valley where waterfalls usually form

Answer 3

Glacier hits an obstacle that is too large/hard to pluck Hitting the obstacle creates pressure and friction increasing melting as the lower ice reaches PMP The meltwater allows the glacier to slide over the rock and smaller rocks abrade the stoss side When the glacier reaches the top of the obstacle friction and pressure drop Meltwater refreezes Frozen rocks are plucked from the lee side

Answer 4

Unsorted glacial material formed through erosion and weathering Form when an ice sheet detaches from the main glacier and melts causing all of the till on top of and within the glacier to deposit on the valley floor

Answer 5

A large boulder that is of a different rock type to the surrounding rock Would have been broken off by weathering and erosion then transported by a glacier and deposited when it has been moved to a different location

Answer 6

Deposits of eroded material that are transported with the glacier Lateral: Material deposited on the sides of a glacier leaving a ridge when the ice melts Medial: Formed when two lateral morains meet in the middle of a glacier and deposit material Ground: Carried under the glacier and abraded between glacier and valley floor. Only sorted moraine Recessional: Forms at the end of a glacier

Answer 7

When a glacier hits an obstacle that cannot be eroded deposition from underneath the glacier builds up behind the obstacle The glacier moves over the large mound and drags excess deposition to the other side Tear drops shape with a long tapered edge Blunt end - stoss side Tapered end - Lee side

Answer 8

Waterlogged soils - thawed soils can’t infiltrate through permafrost and evaporation rates are low Strong winds Low levels of precipitation Low insulation Short growing season - no more than 60 days

Answer 9

Slow nutrient cycles Climate means decomposers can’t thrive Cold, harsh climate with little rainfall - only highly adapted vegetation can grow such as mosses and lichen Overall there is a cycle where poor vegetation creates poor soil and poor soil causes poor vegetation

Answer 10

Heavy snowfall in winter In summer there is heavy rainfall aswell meltwater Mild temps stimulate plant growth, thawing and decomposition Alpine vegetation is decomposed more quickly than in a polar climate, and grows quicker too due to soil fertility and climate. The nutrient rich vegetation allows a more fertile soil to develop when it decomposes, as the nutrients are transferred into the soil. This fertile soil allows more nutrient rich plants to grow.

Answer 11

Temperatures are consistently below freezing. The latitude of some permafrost regions also assists in the consistently cold temperatures, as winters in higher latitudes last longer with less daylight hours, making them colder. Vegetation is more prevalent than in polar regions, but only highly adapted plants can survive in the cold temperatures with little rainfall. The temperatures and poor soil leads to a slow nutrient cycle. The lack of nutrient rich plants contributes to the soil infertility. The cold climate causes the lower ground to be frozen all year around. However, slightly warmer summer temperatures cause the thawing of upper soil called the active layer. Soil is usually extremely waterlogged in summer due to thawing, which means plants become deoxygenated within the soil and cannot survive, and any nutrients are often leached out.

Answer 12

Vegetation grows close to ground - protects from strong winds Shallow roots - To allow it to get nutrients from the active layer Can photosynthesise at low temps - due to low temps from albedo effect, they can create energy Perennial plants - store food to allow them to survive during harsh winters

Answer 13

Northern USA most lakes are freezing later and thawing earlier than 150 days ago - many isolated communities and the oil and gas industries rely on frozen rivers and lakes to transport vital supplies including drilling equipment, building materials

Answer 14

Globally 90% of glaciers are losing ice mass A gradual decrease in ice has been recorded since the 1850s with a short period of gain around 1970, but in the decades since the rate of loss has been unprecedented Millions of people rely on glacial meltwater as their freshwater supply so this would reduce the amount of freshwater available to these communities Reduce opportunities for tourism in places such as the alps

Answer 15

Studies show that rate of sea level rise for most of the 20th century was about 1.7mm per year. In 2019 NASA reported the current average rate is about 3.4mm per year - leading to the loss of land globally and this can cause the displacement of people in Tuvalu and the Maldives

Answer 16

Latitudes between 40 degrees North and 70 degrees North could rise betweeb 5 degrees and 8 degrees by 2100, due to the loss of sea ice and snow cover reducing albedo rates - higher temperature will increase the rate of ice and permafrost melting

Answer 17

North - tundra environment with permafrost South - relatively milder conditions One of the most sparsely populated places on earth - nearly 1/2 of its 750000 residents live in Anchorage Since the 1980s approximately 100,000 inuit have been joined by permanent settlers

Answer 18

Abundant mineral resources (coal, gold, copper) Gold rush in the 1800s 20% of Alaska's mineral wealth lies in gold

Answer 19

1/3 of the state's income comes from the industry which employs over 100,000 people Oil is transported from Prudhoe Bay in the north to valdez in the south by the trans-alaskan pipeline The pipeline is raised above the land to avoid melting the permafrost, which could cause the pipeline to break

Answer 20

Fishing industry employs 80000 people in Alaska - worth $8 billion to the economy Indigenous people use fish to provide food, clothing and oil as part of their subsistence lifestyle

Answer 21

Alaska attracts over 2 million tourists each year 60% of summer tourists arrive via cruise

Answer 22

Winter temperatures can drop below -30 degrees in the north of Alaska This along with limited sunlight makes working outside very challenging

Answer 23

Roads are built on raised gravel beds to reduce heat transfer which can thaw the permafrost Many domestic services such as freshwater and sanitation have to be provided above ground in insulated utilidors to minimise the risk of freezing pipes and thawing the permafrost. In addition, runways are painted white to reflect the energy and reduce heat transfer from the sun