unit 3 outcome 1: MGIS key terms

Question 1

What are ice sheets?

Answer 1

vast masses of ice that are not confined to valleys and domed in shape

Question 2

What are glaciers?

Answer 2

body of ice thats formed on land and in motion, confined by terrain such as valleys and are slow moving

Question 3

what is the last glacial maximum?

Answer 3

most recent period in the earths history when glaciers were at the thickest and sea levels were at their lowest

21-18k calendar years ago roughly

Question 4

what is the holocene climatic optimum?

Answer 4

roughly warm period roughly 9 thousands years before the present with a thermal maximum around 8 thousand years before the present

Question 5

what is the cyrosphere?

Answer 5

all components of the earths surface, below, above land and oceans surface where it is frozen

Question 6

what are the categories?

Answer 6

-sea ice
-land covered by glaciers
-land covered by ice sheets
-land such as tundra covered by snow every winter
-land underlain by permafrost
-peri-glacial zones on margins of ice bound land

Question 7

what is a tundra?

Answer 7

biome where tree growth is less due to cold temperature and short growing seasons

Question 8

what is permafrost?

Answer 8

permanently frozen layers on or below earths surface

Question 9

what are peri-glacial zones?

Answer 9

cold climate frequently marginal to glacial environments

Question 10

whats accumulation?

Answer 10

annual snowfall and ice that is gained by a glaciers that doesnt melt during summer periods

Question 11

what is terminus?

Answer 11

where glaciers start to melt

Question 12

what is ablation?

Answer 12

loss and melting of ice and snow from a glacier

Question 13

what is the equilibrium line?

Answer 13

ablation is equal to accumulation

Question 14

what is the glacial mass balance?

Answer 14

gain or loss of ice from glacial systems

Question 15

Natural causes of MGIS: Variations in solar energy?

Answer 15

> solar radiation that the sun emits is absorbed by the earth, amount absorbed is different for different parts of the earth

> eliptical orbit of the earth influences the natural cycles of global glaciation and warming

Question 16

Natural causes of MGIS: oceanic circulation changes?

Answer 16

> direction of oceanic current change overtime, changing climates of many continents as a result

> impact exchange of heat between oceans and atmosphere

> La nina = warmer ocean temps

> El nino = colder ocean temps

Question 17

Natural causes of MGIS: Volcanic activity?

Answer 17

> volcanic dust and gases can either warm or cool the earth for example some dust can cool earth by reflecting suns radiation

> e.g mount agung released mounts of ash from its eruption which reflected solar radiation and reduced global temp by 0.5 degrees celsius for 2 years

Question 18

Natural causes of MGIS: Plate tectonics?

Answer 18

> movement of continents change oceanic and atmospheric circulation patterns

> landmasses drift overtime and collide with other land masses changing latitudes of those masses

Question 19

Causes of MGIS overview?

Answer 19

> consistent with warming of the earth by global warming which then increased ablation of glaciers in summer periods

> since 1970s earths surface temperature increased 0.94 degrees celsius which correlates to loss of ice in the artic

> industrialisation and fossil fuels increase air temperature, humidity, ocean temperature and heat which led to decline in ice in the artic due to rapid ablation

Question 20

How has spatial distribution of MGIS changed?

Answer 20

> fewer glaciers from 2010-2015 as temperature is very warm

> geologists have identified number of ice ages in last 2000s years have had its ice levels increase

> south cascade glacier in USA has lost half its volume during 1959 to 2010 with ice lose increasing 2010 onwards

Question 21

Human activities causing MGIS: alteration of gases in the atmosphere?

Answer 21

industrialisation has lead to the injection of greenhouse gases into the atmosphere, 60% being released from cities

methane releases areas of sub-artic permafrost which is a major issue and challenge

Question 22

Human activities causing MGIS:
Alteration of landscape?

Answer 22

changes in solar radiation absorption due to building of cities and destruction of forests have lead to less CO2 being absorbed by trees leading to more greenhouse gases in the atmosphere

it can also lead to soil imbalance, change moisture in atmosphere leading to change in wind, heat spread across continents

Question 23

Human activities causing MGIS: Direct additions to atmospheric heat?

Answer 23

burning of fossil fuels and burning of forests contribute to the most C02 because of more absorption

Ash and dust from australian black summer fires have caused 300+ new zealand glaciers to speed up melting up to 30%

Question 24

Impacts of MGIS ON ESE:
Sea level rise?

Answer 24

in the 20th century sea levels rose by 20cm due to melting of glaciers and ice sheets.

Greenland is losing aproximately 250km squared of ice directly into the sea per year

rising sea levels puts coastal islands and cities at great risk of storm surges and flooding, 2/3 of cities with a population higher than 5million are at higher risk

Question 25

Impacts of MGIS on ESE: People movement?

Answer 25

residents of tuvala have become climate refugees because of coastal flooding inundating land due to melting glaciers inuit natives in alaska and canada have move to non traditional ways of living as the melting glaciers have caused their native species and food they hunt for to die

Question 26

impacts of MGIS on ESE: Agricultural input?

Answer 26

UNDP have estimated that crop yields will decline by 30% by 2050 many global productive food bowls on rivers are vulnerable to soil salinisation and inundation e.g in Mekong and Ganges grow 90% of worlds rice

Question 27

Impacts on MGIS on ESE: freshwater resources?

Answer 27

glaciers store 75% of the earths freshwater and act as natural resoivors storing water in winter and releasing in summer enlarged glacial lakes and outburst flooding leads to freshwater becoming salty

Question 28

impacts of MGIS on ESE: Plant and animal communities?

Answer 28

change in temperature can influence migration patterns, altitude changes and reproduction changes loss of species, biodiversity and polar ecosystems

Question 29

impacts of MGIS on ESE: Disease?

Answer 29

as temperature increases due to less absorption of solar radiation from ice from glaciers, diseases like malaria can be carried by mosquitos and spread around the world cold climate can prevent diseases from spreading or even surviving , therefore less cases and deaths for people and animals in those areas

Question 30

impacts of MGIS on ESE: Natural disasters?

Answer 30

expanding populations and deforestations have made flooding worse in himalayan regions Glaciers melting have caused natural disasters like flooding which impact villages close to glaciers, downstream them