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Listen to an Academic Talk Test #007
Listen to an Academic Talk
1. What is the main topic of the talk?
A) The movement of tectonic plates
B) The formation of underwater geysers
C) The composition of seawater
D) Life forms found in the deep ocean
2. According to the lecturer, why does the water from a hydrothermal vent not boil?
A) It does not contain enough salt.
B) It is cooled quickly by the surrounding ocean.
C) It is under extremely high pressure.
D) It is mixed with minerals from the rock.
3. What can be inferred about the crust at mid-ocean ridges?
A) It is much thicker than other parts of the ocean floor.
B) It is geologically very old and stable.
C) It contains a high concentration of soluble minerals.
D) It is completely solid with no cracks.
4. The lecturer mentions "black smokers" as an example of what?
A) A type of deep-sea organism
B) A region where tectonic plates collide
C) A process that cools down magma
D) A structure formed by mineral deposits
Lecturer: Alright, let's dive deep... literally. Today's topic is hydrothermal vents.
Think of them as geysers on the ocean floor.
They're typically found along mid-ocean ridges, where tectonic plates are pulling apart.
What happens is, cold seawater seeps down into cracks in the seafloor.
As it gets closer to the magma chamber beneath the crust, it gets superheated—sometimes to over 400 degrees Celsius.
Now, it doesn't boil because of the immense pressure at that depth.
As this hot water circulates, it dissolves minerals from the surrounding rock.
Eventually, this hot, mineral-rich fluid shoots back up into the ocean.
When it hits the near-freezing seawater, the dissolved minerals instantly solidify, creating tall, chimney-like structures.
These are often called 'black smokers' because of the dark plume of mineral particles.
It's a fascinating process that supports entire ecosystems independent of sunlight.
Think of them as geysers on the ocean floor.
They're typically found along mid-ocean ridges, where tectonic plates are pulling apart.
What happens is, cold seawater seeps down into cracks in the seafloor.
As it gets closer to the magma chamber beneath the crust, it gets superheated—sometimes to over 400 degrees Celsius.
Now, it doesn't boil because of the immense pressure at that depth.
As this hot water circulates, it dissolves minerals from the surrounding rock.
Eventually, this hot, mineral-rich fluid shoots back up into the ocean.
When it hits the near-freezing seawater, the dissolved minerals instantly solidify, creating tall, chimney-like structures.
These are often called 'black smokers' because of the dark plume of mineral particles.
It's a fascinating process that supports entire ecosystems independent of sunlight.
Highlights
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