Questão 1 Comentada - Quadro Complementar de Oficiais da Marinha (Quadro Complementar) - Segunto Tenente Educação Física - Marinha (2025)

Read the text below and answer question.


TEXT I


The world's strongest ocean current should be getting faster - instead, it is at risk of failing.


Antarctica's remote and mysterious current has a profounp influence on the climate, food systems and Antarctic ecosystems. Can we stop it weakening by 2050? The Antarctic Circumpolar Current is the strongest ocean current on the planet. It's five times stronger than the Gulf Stream and more than 100 times stronger than the Amazon River. It forms part of the global ocean "conveyor belt" connecting the Pacific, Atlantic and Indian oceans. The system regulates Earth's climate and pumps water, heat and nutrients around the globe. But fresh, cool water from melting Antarctic ice is diluting the salty water of the ocean, potentially disrupting the vital ocean current.


The Antarctic Circumpolar Current is like a moat around the icy continent. The current helps to keep warm water at bay, protecting vulnerable ice sheets. It also acts as a barrier to invasive species such as southern bull kelp and any animals hitching a ride on these rafts, spreading them out as they drift towards the continent. It also plays a big part in regulating the Earth's climate.


The influence of climate change:
Ocean currents respond to changes in temperature, salt levels, wind patterns and sea ice extent. So the global ocean conveyor belt is vulnerable to climate change on multiple fronts. Previous research suggested one vital part of this conveyor belt could be headed for a catastrophic collapse. Theoretically, warming water around Antarctica should speed up the current. This is because density changes and winds around Antarctica dictate the strength of the current. Warm water is less dense (or heavy) and this should be enough to speed up the current.


Far-reaching consequences:
The consequences of a weaker Antarctic Circumpolar Current are profound and far-reaching. As the main current that circulates nutrient-rich waters around Antarctica, it plays a crucial role in the Antarctic ecosystem. Weakening of the current could reduce biodiversity and decrease the productivity of fisheries that many coastal communities rely on. It could also aid the entry of invasive species such as southern bull kelp to Antarctica, disrupting local ecosystems and food webs.


(Adapted from: www.bbcnews/fuure/article/20250303-the-worldsstrongest-ocean-current-is-at-risck)


According to the excerpt below, mark the correct conjunction that can be replaced for another, without changing the meaning of the text.

"But fresh, cool water from melting Antarctic ice is diluting the salty water of the ocean, potentially disrupting the vital ocean current."

  • A Since
  • B When
  • C However
  • D Moreover
  • E Because