Lecture 1 - Valley Glaciers and the state of the system

Flashcards covering key concepts from a lecture on glacial systems, including glacier formation, distribution, types, and their role in regulating Earth's climate, as well as current challenges like mass loss due to climate change.

Why are glaciers and ice sheets important regulating agents of planet Earth?

They regulate Earth's systems by interacting with and driving climate, storing fresh water, and providing nutrients to ecosystems.

How do glaciers affect ocean currents?

Fresh water from melting glaciers mixes with saline ocean water, altering ocean currents and heat distribution.

What are the key nutrients contained in glaciers and ice sheets?

Nitrate, phosphate, and silica.

How can studying glaciers help us understand climate change?

By understanding their mechanics, we can learn how they shaped climate in the past, present, and future.

What elements make up the glacial systems course?

Lectures, practicals, seminars, drop-in sessions, and a discussion forum on Moodle.

How do practicals enhance learning in the glacial systems course?

By providing data sets to explore concepts in-depth and run models.

What is the purpose of the seminars in the glacial systems course?

To discuss the context of an article and link it back to the lecture.

What is the breakdown of the assessment for the glacial systems course?

50% coursework and 50% exam.

What is a glacier?

A river of ice that flows and is constrained by topography, interacting with the climate.

What is an ice sheet?

A massive body of ice, millions of kilometers squared, unconstrained by topography, depressing the landscape.

What is the term for the sinking of landscape due to the mass of an ice sheet?

Isostatic depression.

How do ice sheets regulate climate?

They block air mass movements and create equator-pole temperature gradients, driving wind systems.

What type of valley do valley glaciers carve out?

A classic U-shaped valley.

What is the term for the area on a glacier where melting occurs?

Melting or ablation zone.

Tarns are features in what type of glacial feature?

A cold cirque glaciers.

What is the name for a feature left behind by a rotating body of ice in the mountains?

Corry hollow, cirque, or coombe.

What two key elements are required for the formation of a glacier?

Snowfall and temperature.

What causes the dark coloration in a snowpack?

Dust accumulating on the snowpack during the summer.

What is overburden pressure?

Pressure increases on the snowpack.

How does snow change over time to form glacier ice?

It metamorphoses from snowflakes into granular ice, then into firn, and finally into pure glacier ice.

Why does glacier ice appear clear?

It is clear because all of the air pockets have been squeezed out.

When does a snow patch or ice patch become a glacier?

When it starts to deform and move under its own weight.

What are the two key controls on the formation and distribution of glaciers?

Latitude and altitude.

How does latitude affect glacier formation?

Low solar angles at high latitudes and high solar angles in the tropics.

What causes the temperature to decrease with increasing altitude?

Adiabatic lapse rate.

What are the micro-topographical factors affecting the distribution of ice sheets?

Aspect, relief, and distance from moisture source.

What is 'aspect' in the context of glacier formation?

The direction a mountain slope is facing.

What are the key mountain glacier areas in the world today?

Alaska, Central and South America, Scandinavia, Central Europe, and other equatorial regions.

What are the key polar glacier areas in the world today?

Antarctica, Arctic Canada, Greenland, Svalbard, and Russian Arctic glaciers.

What are the key impacts of glaciers on the Earth system?

Sea level rise sea level, river runoff, nutrient release, and ocean dynamics.

Which glaciers have experienced the most mass loss?

Alaskan glaciers.

When did most glacierized regions around the world start showing declines in mass?

The nineteen nineties.

What is especially heightened with the increase in temperature around Scandanavia, allowing glaciers to be further nourised?

Moisture content in the atmosphere.

Besides sea levels, what has been greatly impacted by the state of valley glaciers?

Nutrient delivery to the oceans.

When will 80% of glaciers be lost by?

In about 2100.

What do the size of the spheres on diagrams regarding glacier maps show?

The amount of mass loss in different areas around the world.

Most glaciers will be here by the 1990s, in terms of mass-balance.

Negative.

Which glaciers in Greenland started losing mass just before February?

Periphery Glaciers

What is the primary driver of glacier mass loss since the 1980s-1990s?

Climate change.

Why is it important to learn about glaciers now?

To understand the impacts that climate change will have in the future.