Final - Snow

Question 1

What are 4 simultaneous estimation problems related to snow?

Answer 1

• the quantity of water held in snowpacks
• the magnitude and rate of water lost to the atmosphere by sublimation
• The timing, rate, and magnitude of snow melt
• The fate of melt water

Question 2

What are the aims of the Canadian Cryospheric Information Network

Answer 2

• To provide a data and information management infrastructure for the Canadian cryospheric research community
• To enhance public awareness and access to cryospheric information and related data
• To facilitate the exchange of information between researchers, northern communities, decision makers, and the public.

Question 3

What are the 3 spatial scales of snow cover distribution?

Answer 3

1. Macroscale: 10-1000 km, influenced by larger scale meteorological effects
2. Mesoscale: 100m-10km, distribution related to wind, terrain variables, and veg cover
3. Microscale: 10-100m, distribution related to variations in air flow patterns and transport

Question 4

Name a tool for measuring snow accumulation.

Answer 4

A snow pillow

Question 5

What three factors affect water flow through snow?

Answer 5

1. internal snowpack structure
2. condition of the snowpack prior to introduction of water
3. amount of water available at the snow surface.

Question 6

What are the 4 liquid water regimes?

Answer 6

1. Capillary: less than 1% free water. Capillary tension holds water
2. Unsaturated: 1-14% free water. Gravity drains water, but air spaces continuous. Pendular Regime
3. Saturated: > 14% free water. Gravity drains water, but air spaces discontinuous. Funicular Regime
4. Melt/freeze: Water melts and refreezes, before draining from snowpack

Question 7

describe basal ice development

Answer 7

On shallow slopes, ponded meltwater may refreeze at the base of the pack, forming ice layers that impede further meltwater infiltration

Question 8

describe subnivean flow

Answer 8

Lateral flow of basal ponded water depending on slope. If snow still present, lateral flow is still through a porous medium. Presence of liquid water in base of snowpack causes rapid destruction of small snow grains, leaving larger grains, and allowing more rapid flow.

Question 9

What are two mechanisms of snow accumulation on glaciers?

Answer 9

• snow fall

- low temperature

Question 10

What are three mechanisms of snow ablation on glaciers?

Answer 10

• sublimation
• rain
• calving

Question 11

What is the difference between primary and secondary permeability

Answer 11

Primary permeability occurs in intact ice and snow, particularly snow and firn with linked pore spaces.

Secondary permeability is tunnels and pathways, the primary meltwater routes in glaciers

Question 12

What constitutes supraglacial flow?

Answer 12

streams, lakes, the snow aquifer

Question 13

What constitutes Englacial flow?

Answer 13

crevasses, moulins, fractures

Question 14

What constitutes subglacial flow?

Answer 14

channels, cavities, sheets, canals, groundwater

Question 15

what is the difference between glacial flow on the surface versus at the base?

Answer 15

Surface flow is dependent on elevation, while base flow is dependent on elevation and pressure

Question 16

What is the difference between the distributed and channelized systems of subglacial flow?

Answer 16

the distributed system is a slow transit system fed by snow melt while the channelized system is a rapid transit system fed by the distributed system and ice melt.

Question 17

Explain the significance of glacial runoff

Answer 17

• acts an important reservoir in late summer in dry places
• stores water for decades or centuries, helping to buffer and regulate streamflow
• significant in alpine regions