midterm two

All of the Earth's settings and environments that are dominated by water in its solid form are referred to collectively as _____________________

The Cryosphere

New data suggests that the Arctic has been warming _______ times as fast as the rest of the planet since 1971.

Three

The Mean Arctic's Surface Air temperatures (Oct-Sept) have been noticeably higher (compared to the local average) than the rest of the globe since the.....

Early 2000s

The cryosphere is often called the "Canary in the Coal Mine" with regards to global warming. What does this refer to?

Canaries used to be carried into coal mines as early detection systems (the birds suffocated before miners would) of dangerous levels of various mine gases

Continuously frozen soil or sediment is referred to as....

Permafrost

True or False? Another name for permafrost is ground ice.

False

True or False? Most icebergs formed initially as sea ice.

False

True or False? All Arctic sea ice melts in the summer

False

Significant continental ice sheets are found today only on these two landmasses...

Antarctica
Greenland

Antarctic ice shelves "grow" through resupply from their glacial source and these two processes....

Freezing of sea water to their base
Snow and ice accumulation on their tops

That part of the glacier in which crevasses grow is said to undergo _______________ deformation.

Brittle

In order to make a mountain glacier you need.....(click all that apply)

Snowfall in the winter
Gentle slope
Little wind exposure
Short summers with low average temperatures

Mountain glaciers "move" through these two means....

Sliding
Internal plastic flow

The area where ice is added to the glacier is known as the zone of accumulation. What is the area called where ice is lost from the glacier?

Zone of ablation

A glacier can loose mass through the following three ways....

Melting
Calving
Evaporation

While a glacier is retreating, its ice is flowing ____________

Towards the valley

Most of the annual but seasonal snow cover is found in the

Northern Hemisphere

Currently, about __% of the Northern Hemisphere experiences an annual snow cover

45%

The June Arctic snow cover extent has been decreasing since the 1960s by around ____________ per decade

13.4%

The duration and extent of annual snow cover in the Arctic is decreasing because of an increase in temperatures and the snow's ______________ albedo.

Decreasing

Study of 6 major Arctic Siberian rivers has shown that ice formation happens ________________ in the year, and lasts __________________ in the Spring, as compared to the 1950s.

Later; Shorter

The most extensive study of over 13,000 Arctic lakes since the late 90s has shown that their ice surface breaks up ______________ in the Spring, compared to prior years.

Earlier and earlier

A study of 420 shallow lakes on the North Slope of Alaska since 1992 has shown that __________ of these lakes are experiencing grounded ice (frozen all the way to the bottom of the lake) conditions, every year.

Fewer

Permafrost that forms consistently every year in the same place but thaws out completely in the Spring and Summer is called....

Discontinuous permafrost

That part atop the continuous permafrost that thaws out in Spring and Summer is called.....

The active layer

The oldest frozen mammoth carcasses retrieved from melting permafrost are around ____________ years old.

45,000

Continuous permafrost temperatures have ________ since the mid-1970s.

Increased (bad news)

With an increase in average annual Arctic temperatures we would expect to see the "active layer" thickness atop permafrost to ________________

Increase

True or False? The depth to which discontinuous Siberian permafrost has been freezing has consistently decreased since the early 20th century.

False

Regional and global satellite measurements of the continuous, discontinuous, and sporadic permafrost areal extent in the Northern Hemisphere suggest an overall ___________ of all of those types since the year 2000.

Shrinkage

Developing irregularities in the land surface, caused by the melting of continuous permafrost, are collectively called....

Thermokarst

True or False? Cryovolcanism, a brand new geomorphic feature, never before seen, is now appearing all over Northern Siberia.

False

The active layer below a lake in the Siberian permafrost is called....

Talik

Before exploding, cryovolcanoes form a surface bulge known as a _____________________

Pingo

The explosion of a cryovolcano is driven by the built-up of _____________________

Methane

_____ of an iceberg's mass is below water

7/8

True or False? The melting of sea ice is one of the major drivers behind global sea level rise

False

The lowest Arctic sea ice extent on record was observed in _________________

2012

Roald Amundsen and his crew, became the first humans to traverse the Northwest Passage in 1906, after being frozen in the sea ice for nearly 3 years. The same passage first became fully navigable due to ice free conditions in _________________

2007

When Arctic Nations noticed that the Northwest Passage had opened for the first time in human history, they......

...immediately squabbled with each other over territorial ownership and land claims.

The loss of and reduced winter and summer sea ice in the Arctic is having measurable affects on local wildlife, coastal erosion rates, and threatens.....

an Indigenous way of life, thousands of years old

Most of the world's remaining ice shelves can be found in ________________________

Antarctica

In 2002, the sudden breakup of this ice shelf made international headlines.

Larsen B

The largest iceberg ever observed broke off the __________________ ice shelf in 2021.

Ronne-Filchner

An immediate result of the break-up of ice shelves is that the glaciers behind them begin to ...........

Surge forward

The largest remaining Arctic ice shelf, which had nearly completely collapsed by 2015, was found off the coast of________________

Ellesmere Island

If precipitation stays constant, warming air temperatures will likely cause mountain glaciers to (click all that apply)

Retreat
Surge
Loose overall mass

There are a handful of mountain glaciers in Scandinavia and New Zealand that are actually advancing and gaining mass. What do these glaciers have in common?

They are near coastal regions where evaporation rates have increased and cause greater snowfall/precipitation in higher altitudes.

Why is the loss of mountain glaciers not just a huge loss for the glacier tourist industry?

all of the above

The areal extent of surface melting of the Greenland Ice Sheet has been increasing, reaching a record 97% in the summer of 2012. While visibly striking, such measurements might or might not be a very precise measure of the actual ____________________ of the ice sheet.

Total mass loss

How do we know that calving events at the fronts of major Greenland glaciers have more than doubled since the early 2000s?

The frequency of calving earthquakes (icebergs >1Gt) has gone up and can easily be detected remotely

Since 2002, a pair of satellites called ______________ have been keeping track of the mass of the Greenland Ice Sheet, which is losing mass around 230 Gt per year since.

Grace

"The shape the sea surface takes due to differences in gravitational attractions across the planet" best describes the ___________-based definition of sea level.

geoid

Match the process to its impact on global sea level
A. increase in sea level
B. decrease in sea level

A - melting glaciers
A - increased absorption of heat by the ocean
A - decrease in salinity
A - increase in seafloor spreading rates
A - increase in sediment input to the ocean
A - decrease in evaporation rates
B - an increase in the volume of rivers and lakes
A - increase in groundwater use for agriculture
A - removal of inland river dams

Which of the following processes cause eustatic sea level changes as a result of changing the total mass of the water in the oceans (choose all that apply)

A - changes in glacial ice balance
F - changes in the amount of atmospheric water storage
G - changes in the volume of river and lake waters
H - changes in the amount of groundwater extraction
I - changes in the number of river dams across the world

Which of the following processes cause eustatic sea level changes as a result of changing the volume (but not the mass) of the water in the oceans (choose all that apply)

B - changes in the rate of thermal expansion of water
C - ocean salinity changes

The melting of continental glaciers causes eustatic sea level rise, and an apparent sea level ___________ in the location the ice melted due to glacial rebound.

drop

Eustatic sea level is rising at 3.4 mm/year. A stretch of coastal mountains in Chile is being uplifted at 3.0mm/year. What is the rate of local sea level change as measured by local tide gauges?

a net sea level increase of 0.4mm/year

Groundwater extraction causes eustatic sea level rise through a change in global ocean water ____________, as well as additional local sea level rise due to soil ________________.

mass; compaction

True or False? A tide gauge attached to a settling pier will record a local rise in sea level that is faster than eustatic sea level rise.

True

Adding mass to coastal regions, ______________ local sea level.

increases

The sea is rapidly rising in the Mississippi Delta due to______________________

sediment compaction

The "noise" this type of signal creates on tidal gauge records can be removed statistically after 19 years of observations.

tides

The current tidal gauge "of choice" across the world is....

the acoustic gauge

This piece of equipment is used in several tide gauge designs to remove the wave noise.

stillwell

Aside from mechanical failure, what other phenomenon requires constant maintenance of mechanical float gauges?

encrustation of stillwell, float, and cables by organisms

What environmental variable must be recorded alongside the acoustic gauge record for an accurate assessment of the data?

air temperature in the stillwell

The first satellite to take measurements of global sea level changes was the.....

Poseidon/Topex

The average rate of global sea level change as measured by satellites since 1993 is....

3.4mm/year

Why is the rate of global sea level changes recorded by tidal gauges so much slower than the rate recorded by satellites?

satellites cover a much greater area in their measurements, and are therefore more reliable

The fastest rate of sea level rise in North Carolina occurs......

at the Duck pier

True or False? Sea level rise projections are best done using linear prediction models based on historical data.

False

The two most important contributors to sea level rise today are....(choose two)

thermal expansion
ice melting

By how much will the global sea level rise if the Greenland ice sheet completely melted?

6 meters

By how much would global sea level rise if the entire Western and Eastern Antarctic ice sheets melted?

60 meters

By 2100 global sea level will most likely rise _______

3-4 feet

The most commonly precipitated mineral by invertebrates in the oceans is....

calcium carbonate

The two primary sources of calcium ions in the oceans are (pick two):

feldspar-rich rock weathering
weathering of carbonates

In the long term, the weathering of terrestrial rocks provides a steady source of carbonate ions to the oceans. What is the most common source of carbonate ions in the short-term?

atmospheric carbon dioxide dissolving in seawater

Match the following compounds and ions, to their names
A. carbonic acid
B. hydrogen ion
C. carbon dioxide
D. carbonate ion
E. calcium carbonate
F. bicarbonate ion

CO2 - carbon dioxide
H2CO3 - carbonic acid
HCO3 - bicarbonate ion
H+ - hydrogen ion
CO3^2- - carbonate ion
CaCO3 - calcium carbonate

H2CO3 → _________ + H+

HCO3-

Increasing dissolved carbon dioxide content in the ocean, affects calcium carbonate-shell-precipitating organism in two ways (choose two)

it results in more H+ ions in the ocean, therefore dramatically decreasing pH (an increase in acidity), increasing dissolution rates of existing shells
it results in more H+ ions to which available carbonate ions bond to, rather than the latter being available to shell-building organisms

Since 1750, the surface ocean ph has decreased by _________ which is equivalent to a ________ increase in hydrogen ions.

-0.1; 30%

True or False? So far, long term (1880-2002) ph-changes in the oceans have been limited to the surface ocean in direct contact with the atmosphere.

False

For this question, please consult the graph in the Changing Oceans lecture, slide 31 (in lecture version). Which of the studied groups showed no significant reaction to increases in ocean acidity?

blue mussel

For this question, please consult the graph in the Changing Oceans lecture, slide 31 (in lecture version). Strangely enough, blue crabs, shrimp, and this other crustacean group showed increased calcification under higher acidity in this study.

lobster

For this question, please consult the graph in the Changing Oceans lecture, slide 31 (in lecture version). Of the groups that support significant fisheries around the world, which saw the greatest reduction in calcification as a result of ocean acidification, in this study?

soft clam

For this question, please consult the graph in the Changing Oceans lecture, slide 31 (in lecture version). Which of following groups actually showed in an initial increase in calcification rate as a result of increased pH, but then followed by calcification rates up to 23% lower than todays in the worst conditions?

Halimeda (green calcareous algae)

Which of the following is the most common ion dissolved in seawater?

chloride

The average salinity of the ocean is at ___________

35 ppt (parts per thousand)

In the Arctic summer, the average surface water salinities are ____________ than they are in the Arctic winter.

lower

Due to its location in the dry subtropics, and its restricted nature, the ______________________ exhibits the highest average ocean salinities.

Mediterranean Sea

The Bay of Bengal, the Northern coast of Brazil, and Samborombón Bay are on average significantly less saline than the surrounding ocean because.....

these areas all receive large amounts of freshwater input from the outflow of large rivers

Which of the following statements best describes the 2005-2013 GLOBAL salinity trends observed in the world's oceans?

The polar regions and tropics are overall experiencing a decrease in surface salinity, whereas the subtropics are experiencing salinity increases.

Which ocean basin "bucks" the trend in global salinity changes in the tropics?

The Atlantic Ocean

More saline waters are ____________ dense than normal seawater, and tend to ______________.

more; sink

Prior to the 1940s, most sea surface temperature measurements were made using ___________.

buckets

The following region has seen the most significant warming of sea surface temperatures on the planet in the last 20 years

The Northern Atlantic (and Arctic)

Water has the unusual ability to absorb a lot of heat, while ____________ changing its temperature significantly.

not

The "AMOC" is driven by.....

a decrease in sea surface temperatures coupled with an increase in salinity