May 27, 2024
Chicago 12, Melborne City, USA

Multiple Choice Single Answer (Reading)

  1. Iceberg
    B-15 broke off from the Ross Ice Shelf in Antarctica. It was the largest iceberg ever documented, with a
    surface area of more than 4,200 square miles — more than twice the size of the state of Delaware.
    After it started breaking up, the largest of its pieces, B-15a, drifted along the coast of Antarctica,
    lingered on a shallow seamount, and collided with an ice tongue, before running aground and breaking
    again. Late in 2007, the largest remaining chunk floated out into the South Pacific where, in the warmer
    water, it began to disintegrate. For the whole of the next year, the ocean was noisier than usual. All the
    way up past the equator, 4,350 miles or so away from where B-15a broke apart, hydrophones that
    scientists from the National Oceanic and Atmospheric Administration (NOAA) had suspended underwater
    were picking up strange signals. Another set of hydrophones, this one in the Juan Fernández Islands, off
    the coast of Chile, picked up the noise, too, even louder. When the scientists used the two sets of data
    to determine the source of the noise, they found the most likely culprits: B-15a and C-19a, another giant
    iceberg. Twenty years ago, not so long before B-15 broke off from Antarctica, “we didn’t even know
    that icebergs made noise,” says Haru Matsumoto, an ocean engineer at NOAA who has studied these
    sounds. But in the past few years, scientists have started to learn to distinguish the eerie, haunting
    sounds of iceberg life — ice cracking, icebergs grinding against each other, an iceberg grounding on the
    seafloor — and measure the extent to which those sounds contribute to the noise of the ocean. While
    they’re just now learning to listen, the sounds of ice could help them understand the behavior and
    breakup of icebergs and ice shelves as the poles warm up.
    Where did the largest piece off from B-15 eventually go?
    A) Seafloor
    B) Antarctica
    C) Chile
    D) South Pacific