Questions 31-35
Complete the notes below.
Write NO MORE THAN TWO WORDS for each answer.
Using radars to predict sea level rise
The answer is study. In the passage, the lecturer says, "That means that I use radar to study glaciers and ice sheets." This shows that glaciologists 'study' glaciers and ice sheets using radar, matching the instruction in the gap fill.
Associated Text:
That means that I use radar to study glaciers and ice sheets.
The answer is hard. The lecturer states, "So today, I want to talk to you about why it’s so hard to put good numbers on sea level rise." This is directly talking about the difficulty ('hard') of making accurate predictions about sea levels, which matches the gap fill requirement.
Associated Text:
So today, I want to talk to you about why it's so hard to put good numbers on sea level rise
The answer is steadily. The lecturer says, "When most scientists talk about sea level rise, they show a chart with steadily rising numbers." This tells us that currently, sea levels are rising steadily, which is the word to fill in the gap.
Associated Text:
When most scientists talk about sea level rise, they show a chart with steadily rising numbers.
The answer is collapses. The lecturer states, "beyond that, such a chart comes with a warning – unless the West Antarctic Ice Sheet collapses. And in that case, we would be talking about dramatically higher numbers." This means that if the West Antarctic Ice Sheet 'collapses,' sea levels will rise much faster.
Associated Text:
beyond that, such a chart comes with a warning - unless the West Antarctic Ice Sheet collapses. And in that case, we would be talking about dramatically higher numbers.
The answer is geologic. The lecturer mentions, "we know from the geologic history of the Earth that there were periods in its history when sea level rose more quickly than today." This means the prediction is based on the 'geologic' history of the Earth.
Associated Text:
we know from the geologic history of the Earth that there were periods in its history when sea level rose more quickly than today.
Questions 36-40
Choose the correct letter, A, B, or C.
Write your answers in boxes 36-40
on your answer sheet.
36. To know whether the ice sheet will collapse, scientists need
37. According to the speaker, ice sheets change
38. Scientists find out about what's happening inside ice sheets by
The answer is A. The lecturer explains that to know whether a significant portion of the ice sheet will collapse, "we need models that we know include all of the processes, conditions and physics that would be involved in a collapse like that." This matches option (A): models.
Associated Text:
we need models that we know include all of the processes, conditions and physics that would be involved in a collapse like that.
The answer is C. The lecturer says, "we now know that ice sheets not only evolve over the timescale of millennia and centuries, but they're also changing over the scale of years and days." This means ice sheets change both over long and short periods, that is, constantly, which matches option (C).
Associated Text:
we now know that ice sheets not only evolve over the timescale of millennia and centuries, but they're also changing over the scale of years and days.
The answer is B. According to the script, "airborne ice-penetrating radar is the main tool we have to see inside of ice sheets. So, most of the data used by my group is collected by aeroplanes with antennas underneath the wing. These are used to transmit radar signals down into the ice." This indicates that scientists find out about what's happening inside ice sheets by sending radar signals into the ice, which matches option (B).
Associated Text:
These are used to transmit radar signals down into the ice.
The answer is A. The lecturer describes a radargram as "a vertical profile through the ice sheet, kind of like a slice of cake." This statement directly matches with (A): a profile of the ice sheet.
Associated Text:
a radargram is a vertical profile through the ice sheet, kind of like a slice of cake.
The answer is A. The lecturer points out, "The ground-penetrating radars that are used to investigate infrastructures of roads or detect landmines struggle to get through a few metres of earth. But we can look through three kilometres of ice. ... ice is basically the perfect target for radar." This shows that radars work especially well for ice, corresponding to option (A).
Associated Text:
But we can look through three kilometres of ice. And there are sophisticated, interesting, electromagnetic reasons for that, but let's say for now that ice is basically the perfect target for radar, and radar is basically the perfect tool to study ice sheets.
