Activity 2.2 – Cyrosphere
Two people standing near the water (University of Washington Libraries, n.d.)
Mendenhall Lake (Forrest Service, n.d.)
Mendenhall Glacier, Alaska between 1950
and 1970 to 2020
Problem
The problem with Mendenhall Glacier is that it has
gone through two periods of rapid retreat according to the American Geophysical
Union (Pelto,2019). Rapid retreat essentially means that the snow is not
accumulating as fast as it is melting. The runoff has now created a reservoir,
which did not exist “until after 1910” (Pelto,2019). Looking at the area the
glacier is shrinking retracting more inward and losing mass. This tells us that
there is some form of heating causing this melting, from either the
“atmosphere, geothermal heat flux, fractional heat due to ice flow” (Lemmons,2022).
Geothermal heat flux is when heat accumulates at the base of the ice sheets
(Lösing, n.d.). Fractional heat due to ice flow seems to be another type of diffusion
of heat. Mendenhall Glacier is predicted to disappear within the next twenty
years as of 2022 (Tongass National Forest – offices, 2022). It seems that the
factors that seem to take the biggest toll on these landmarks is green house
gas emissions that are heating our environment heating from the outside in (NASA.,
n.d.).
Explanation
From my interpretation of the information, the glacier
seems to be melting due to one of the above-mentioned types of heat transfer. They
seem to transfer heat in different areas of the glacier. A big determining
factor for this is the rate at which they get snow fall or rain versus the rate
that it is melting. I am assuming any type of heating would be detrimental towards
the glacier seeing as it had not seen enough snow fall in years past. The
reason for the melting is the increasing temperatures causing a larger summer
melting (Pelto,2019) due to greenhouse gas emissions. Luckily in 2018 the
snowline reached 1500 meters, a record, and will hopefully be able to buy the glacier
a bit more time.
References
Two people standing near water, Mendenhall Glacier,
Alaska, probably between 1950 and 1970.
digitalcollections.lib.washington.edu. (n.d.). Retrieved September 12, 2022,
from https://digitalcollections.lib.washington.edu/digital/collection/alaskawcanada/id/4404/
Welcome to the Mendenhall Glacier Visitor Center .
Forest Service National Website. (n.d.). Retrieved September 12, 2022, from
https://www.fs.usda.gov/detail/tongass/about-forest/offices/?cid=stelprdb5400800
Source: “Mendenhall Glacier.” 58 degrees 26’27.49”N 134
degree 32’45.23”W 901 E. Google Earth Pro July 28,2020. September
12, 2022
Encyclopedia.com. (2022, September 13). ."
environmental science: In context. . encyclopedia.com. 25 Aug. 2022 .
Encyclopedia.com. Retrieved September 13, 2022, from
https://www.encyclopedia.com/environment/energy-government-and-defense-magazines/glacial-retreat#:~:text=A%20glacier%20grows%20wherever%20snow,been%20retreating%20since%20about%201850.
Pelto, M. (2019, July 19). Mendenhall Glacier, Alaska
accumulation zone shrinks. From a Glacier's Perspective. Retrieved September
13, 2022, from
https://blogs.agu.org/fromaglaciersperspective/2019/07/17/mendenhall-glacier-alaska-accumulation-zone-shrinks/
Lemmons, R. (2022, August 13). Temperature distribution
in glaciers and ice sheets - environmental change. Climate Policy Watcher.
Retrieved September 13, 2022, from https://www.climate-policy-watcher.org/environmental-change/temperature-distribution-in-glaciers-and-ice-sheets.html
Lösing, M., Ebbing, J., & Szwillus, W. (1AD, January
1). Geothermal heat flux in Antarctica: Assessing models and observations by
bayesian inversion. Frontiers. Retrieved September 13, 2022, from https://www.frontiersin.org/articles/10.3389/feart.2020.00105/full
Tongass National Forest - offices. Forest Service
National Website. (n.d.). Retrieved September 13, 2022, from https://www.fs.usda.gov/detail/tongass/about-forest/offices/?cid=stelprdb5401454
NASA. (n.d.). What is the greenhouse effect? NASA.
Retrieved September 13, 2022, from
https://climatekids.nasa.gov/greenhouse-effect/
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