Reading Practice Test 7: Mind and Ocean

Read the text below and answer questions 1-13.

Mapping the Ocean Floor

More than eighty percent of the world's ocean floor remains unmapped in any detail, a fact that surprises most people given how thoroughly the surface of Mars has been photographed. The reason is straightforward: water blocks the radar and optical imaging that work so well from orbit, forcing ocean scientists to rely on sound instead of light.

The primary tool is sonar, which measures depth by timing how long a sound pulse takes to travel to the seabed and echo back. Early single-beam sonar produced only a narrow strip of depth data directly beneath a ship, meaning that mapping an entire ocean basin this way would take centuries of continuous surveying. Modern multibeam sonar systems, developed by oceanographer Teresa Vance and her engineering team, fire dozens of angled sound pulses simultaneously, building a wide swath of seafloor data with each pass of the ship — dramatically cutting the time needed to survey a given area.

Even with multibeam sonar, ships can only cover a limited amount of ocean, and dedicating vessel time to systematic mapping is expensive. Vance's team has increasingly relied on a second, cheaper source of data: satellite altimetry. Seafloor features such as underwater mountains exert a tiny but measurable gravitational pull, which causes the ocean surface directly above them to bulge upward by a few centimetres. Satellites can detect these subtle bulges from orbit, allowing researchers to infer the rough shape of the seafloor across vast areas without a single ship ever passing overhead.

Satellite-derived maps, however, lack the fine detail that ship-based sonar provides; they can reveal that a seamount exists but not its exact height or shape. Vance argues that the two methods are complementary rather than competing: satellite data guides ships toward areas most likely to contain interesting or previously unknown features, allowing limited and expensive ship time to be used far more efficiently than random or evenly spaced surveying ever could.

The push to complete a full high-resolution map of the ocean floor has accelerated in recent years, driven partly by scientific curiosity and partly by practical concerns: submarine cables, offshore wind farms, and fishing fleets all benefit from accurate seabed charts, while unmapped regions have occasionally hidden hazards discovered only after a ship ran aground on a previously unknown feature. Vance estimates that at the current pace of combined satellite and ship-based mapping, a complete high-resolution map of the entire ocean floor could be achieved within the next two decades — a timeline she readily admits depends heavily on sustained international funding.

Read the text below and answer questions 14-26.

The Psychology of Nostalgia

For much of the twentieth century, nostalgia was treated by psychologists as a mild form of homesickness at best, and a psychological disorder at worst — the term itself was coined in the seventeenth century to describe a debilitating condition among soldiers stationed far from home. Only in the past two decades has research consistently shown the opposite: that nostalgia, far from being harmful, appears to serve several beneficial psychological functions.

Psychologist Daniel Ferro and colleagues have run a series of studies asking participants to describe a nostalgic memory in detail, then measuring changes in mood, sense of meaning, and feelings of social connection immediately afterward. Across these studies, participants who engaged in nostalgic reflection consistently reported improved mood and a stronger sense that their life had meaning and continuity, compared to control groups asked to think about an ordinary recent event. Notably, the effect appeared regardless of whether the nostalgic memory itself was happy or bittersweet — even memories tinged with sadness produced a net positive shift in mood.

One explanation Ferro's team proposes is that nostalgia functions as a psychological resource specifically activated during difficult periods. In several studies, participants who were first made to feel lonely, or given a task designed to lower their sense of belonging, spontaneously engaged in more nostalgic reflection than participants who had not been put in that state, and those who did so afterward reported reduced feelings of loneliness. Nostalgia, in this view, is not an aimless drift into the past but a targeted response that helps restore a sense of social connection when it is threatened.

Nostalgia also appears to play a role in identity, particularly during major life transitions. Ferro's research on university students found that nostalgic reflection increased notably around transition points — beginning university, graduating, moving to a new city — periods when a stable sense of self is often disrupted. Students who reported higher levels of nostalgic reflection during these transitions also reported greater confidence in navigating the change, suggesting nostalgia may help maintain continuity of identity even as circumstances shift dramatically.

Not all researchers agree that nostalgia is uniformly beneficial. Some caution that excessive reliance on nostalgic reflection, particularly when used to avoid engaging with present difficulties rather than to cope with them temporarily, could in theory become counterproductive, though long-term studies on this possibility remain limited. Ferro himself is cautious about overstating the case, noting that his studies measure short-term mood and meaning effects rather than long-term wellbeing, and that more research is needed before nostalgia could be recommended as a deliberate therapeutic tool.