biosci 100 EARTH ATMOS mcq prep

the frozen continent 2026 s2 mid sem test

the antarctic convergence (or polar front) is roughly: a) 4 km wide b) 40 km wide c) 400 km wide d) 4000 km wide

b) 40 km wide

the expansion of dry air at high elevations: a) triggers the formation of katabatic winds b) causes the air to warm by about 1°c for every 100m of elevation c) causes the air to cool by about 1°c for every 100m of elevation d) increases the moisture-carrying capacity of the air

c) causes the air to cool by about 1°c for every 100m of elevation

as air draining from the interior of antarctica approaches the sea coast, it: a) is deflected towards the east by the coriolis force b) is not affected by the coriolis force c) is compressed by the increasing air pressure d) expands at the lower elevations

c) is compressed by the increasing air pressure

in the southern hemisphere, the coriolis force acts on moving: a) air b) water c) solid bodies d) all of the options are correct

d) all of the options are correct

the ekman spiral: a) drives net surface ocean water transport to the right in the southern hemisphere b) contributes to the vertical exchange of nutrients and oxygen between deep and shallow waters c) was named after a french oceanographer d) continues down to the bottom of the ocean

b) contributes to the vertical exchange of nutrients and oxygen between deep and shallow waters

of the following, which could experience continuous sunlight for periods of 24 hours or more? a) balleny islands (67°s) b) campbell island (52°33's) c) south magnetic pole (64°31's) d) hobart, tasmania (42°54's)

a) balleny islands (67°s)

what was the major consequence of the establishment of a substantial circum-antarctic current around 23 million years ago? a) the thermal isolation of antarctica b) the formation of the transantarctic mountains c) the initiation of glaciation in antarctica d) the extinction of antarctic dinosaurs

a) the thermal isolation of antarctica

mount erebus is: a) made of beacon sandstone, injected with ferrar dolerite b) in the dry valleys c) a volcano d) a nunatak

c) a volcano

at the south geographic pole, how far above the horizon does the sun get at mid-winter (21/22 june)? a) 23°27' b) 66°33' c) 90°00' d) 0°00'

d) 0°00'

the transantarctic mountains: a) started to form about 180 million years ago b) represent a former region of continental collision and subduction c) are at the centre of the east antarctic ice sheet d) are mainly comprised of volcanic rocks

b) represent a former region of continental collision and subduction

antarctic bottom water: a) flows northwards b) is relatively dense c) is relatively well oxygenated d) all of the options are correct

d) all of the options are correct

the coldest place on earth is: a) vostok station b) dumont d'Urville station c) south pole station d) mcmurdo station

a) vostok station

which of the following is not correct? milankovic cycles: a) are made up of 100,000, 41,000 and 21,000 year cycles b) refer to the switching on and off of the circum-polar current c) influence the intensity and warmth versus cold of the seasons d) have influenced global temperatures over at least the past 2.6 million years

b) refer to the switching on and off of the circum-polar current — this is false; milankovic cycles are about orbital variations, not the current

which in the list below does not apply to a description of the antarctic continent? a) driest b) coldest c) wettest d) highest

c) wettest

the antarctic convergence (polar front) is best described as: a) a zone in the southern ocean where circumpolar deep water approaches the surface to cool it b) a 40 km wide zone where the sea temperature at the bottom shows a significant 2-3°c decrease as you progress in a southerly direction c) a zone in the southern ocean north of 60°s d) none of these options is correct

b) a 40 km wide zone where the sea temperature at the bottom shows a significant 2-3°c decrease as you progress southward

katabatic winds flowing off the polar plateau towards the antarctic coastline are deflected in which direction by the coriolis force? a) northwards b) eastwards c) westwards d) southwards

c) westwards

antarctic coal beds: a) are currently only mined commercially by russia b) are consistently of high quality, with low moisture and ash content c) were originally laid down in the cambrian period, 543-490 million years ago d) are found in the transantarctic mountains

d) are found in the transantarctic mountains

which of the following contribute to antarctica being the coldest place on earth? a) high elevation of the interior b) all of these options are correct c) thermal isolation by circum-antarctic winds and currents d) high albedo

b) all of these options are correct

how do we know that the antarctic ice sheets have oscillated in size over the quaternary period? a) all of the options are correct b) global sea-levels have oscillated in synchrony with temperature changes inferred from the ice cores c) the andrill program demonstrated that the antarctic ice sheets have advanced and retreated repeatedly over that time d) ice cores contain a record of past temperature fluctuations

a) all of the options are correct

which of the following do not help explain why antarctica is so cold? a) dryness of the antarctic atmosphere b) albedo c) thermal isolation of antarctica d) short summer days below the antarctic circle

d) short summer days below the antarctic circle — this is actually backwards; summer days are long (continuous daylight) south of the antarctic circle, so this does not help explain the cold

during the cambrian period (about 542 ma) the antarctic landmass was: a) covered by an extensive ice cap b) located close to the equator c) a cold, deep sea devoid of life d) a mountainous region covered by extensive forests

b) located close to the equator (as part of gondwana, in a warm climate)

about when did gondwana begin to split up? a) jurassic (200-146 ma) b) permian (299-251 ma) c) cambrian (543-490 ma) d) eocene (56-34 ma)

a) jurassic (200-146 ma)

the west wind drift: a) occurs closer to the antarctic continent than the east wind drift b) creates an easterly flowing current c) is separated from the east wind drift by the antarctic convergence d) arises from sub-antarctic katabatic winds turning left as they approach antarctica

b) creates an easterly flowing current (it's the driver of the antarctic circumpolar current)

on the polar map, in the band of ocean (the antarctic circumpolar current) between the solid circles and the outlined squares, the predominant current flows: a) anticlockwise b) clockwise c) from south to north d) from north to south

b) clockwise

katabatic winds flowing off the polar plateau towards the antarctic coastline are deflected in which direction by the coriolis force? a) south b) west c) east d) north

b) west

the discovery of fossils of the fern-like glossopteris provide evidence that: a) antarctica was once connected to other southern landmasses b) antarctica once had a warm wet climate c) plants have recently been present on the antarctic continent d) dinosaurs were present on the antarctic continent

a) antarctica was once connected to other southern landmasses (classic evidence for gondwana / continental drift)

the transantarctic mountains stretch ~3500 km, dividing antarctica into east and west. which of the following is correct? a) the continental crust beneath the west antarctic ice sheet sits above sea level, while east antarctica's crust sits below sea level due to isostatic pressure b) east antarctica is underlain by a single thick ancient block of continental crust c) east antarctica is the smaller portion attached to the antarctic peninsula d) if the west antarctic ice sheet were removed, west antarctica would form a single mountain mass (massif)

b) east antarctica is underlain by a single thick ancient block of continental crust

in the diagram of antarctic ocean fronts (labels a-e, showing ice shelf, ice edge, circumpolar deep water, abyssal depths, shelf water, continental slope), label b is: a) the antarctic divergence b) the antarctic convergence c) the antarctic coastal current (acoc) d) the antarctic circumpolar current (acc)

a) the antarctic divergence

in the diagram of antarctic ocean fronts, the current labelled d is aided by: a) the antarctic convergence b) the great ocean conveyor belt c) the west wind drift d) katabatic winds

d) katabatic winds — they help drive the coastal current (east wind drift/acoc) via the coriolis effect