Mid-Ocean Ridges Worksheet
Introduction to Mid-Ocean Ridges:
http://oceanexplorer.noaa.gov/edu/learning/player/lesson02.html
1: Who is the NOAA?
The NOAA is the National Oceanic and Atmospheric Administration. A government Agency in charge of all underwater exploration.
2: What is the mid-ocean ridge system? What happens there?
A 65,000 km. long system of ridges, where new sea-floor is created. Formed by places under the ocean where plates meet in a divergent boundary.
3: How long/wide the is mid-ocean ridge system? Where is it located?
It is 65000 km. long and 1500 km. wide.
4: What type of plate boundary forms a mid-ocean ridge system? Explain.
It is located underneath the sea at divergent plate boundaries. where the sea floor is being spread apart and new ocean crust forms.
5: Explain how ridges form:
Lava flows into the valley formed by a divergent boundary. As the tectonic plate thins, magma starts to come up and fill the cracks. The crust around this now denser rift zone starts to rise up and form ridges.
6: What forms most of the ocean crust?
Most of the ocean crust is made of basaltic dikes, in the lower 7-9 kilometers of the crust, which is made by magma that cools before it leaves the crust.
7: How does hot lava respond to cold sea water? (Pillow Basalt)
(I googled this) The outer layers of the magma quickly harden but the inside cools slower and keeps moving for a little while, creating a pillow shape.
8: What is happening at the Juan de Fuca Ridge?
New crust is being formed, spreading the ridge as much as 6 meters every hundred years.
9: What does the rate of spreading dictate?
I don't know, I wasn't there.
10: How hot can sea water be heated to at the mid-oceanic ridges?
400 degrees C
11: Explain how HYDROTHERMAL Vents are formed:
Seawater seeps through cracks in the crust near mid-ocean ridges. As it does this, it heats up to boiling temperatures. Eventually it finds its way to the surface of the crust and spurts upwards like underwater hot springs. The water also carries minerals with it.
12: Why is the hot mineral water so important? What do they support?
The mineral water is important because it supports a variety of strange life that only exists at hydrothermal vents.
13: What is chemosynthesis? How does it differ from photosynthesis?
Chemosynthesis is a chemical process where small animals and bacteria without sunlight use basic chemicals to create food. They will oxidize gases like methane (from thermal vents) or hydrogen to gain energy.
http://oceanexplorer.noaa.gov/edu/learning/player/lesson02.html
1: Who is the NOAA?
The NOAA is the National Oceanic and Atmospheric Administration. A government Agency in charge of all underwater exploration.
2: What is the mid-ocean ridge system? What happens there?
A 65,000 km. long system of ridges, where new sea-floor is created. Formed by places under the ocean where plates meet in a divergent boundary.
3: How long/wide the is mid-ocean ridge system? Where is it located?
It is 65000 km. long and 1500 km. wide.
4: What type of plate boundary forms a mid-ocean ridge system? Explain.
It is located underneath the sea at divergent plate boundaries. where the sea floor is being spread apart and new ocean crust forms.
5: Explain how ridges form:
Lava flows into the valley formed by a divergent boundary. As the tectonic plate thins, magma starts to come up and fill the cracks. The crust around this now denser rift zone starts to rise up and form ridges.
6: What forms most of the ocean crust?
Most of the ocean crust is made of basaltic dikes, in the lower 7-9 kilometers of the crust, which is made by magma that cools before it leaves the crust.
7: How does hot lava respond to cold sea water? (Pillow Basalt)
(I googled this) The outer layers of the magma quickly harden but the inside cools slower and keeps moving for a little while, creating a pillow shape.
8: What is happening at the Juan de Fuca Ridge?
New crust is being formed, spreading the ridge as much as 6 meters every hundred years.
9: What does the rate of spreading dictate?
I don't know, I wasn't there.
10: How hot can sea water be heated to at the mid-oceanic ridges?
400 degrees C
11: Explain how HYDROTHERMAL Vents are formed:
Seawater seeps through cracks in the crust near mid-ocean ridges. As it does this, it heats up to boiling temperatures. Eventually it finds its way to the surface of the crust and spurts upwards like underwater hot springs. The water also carries minerals with it.
12: Why is the hot mineral water so important? What do they support?
The mineral water is important because it supports a variety of strange life that only exists at hydrothermal vents.
13: What is chemosynthesis? How does it differ from photosynthesis?
Chemosynthesis is a chemical process where small animals and bacteria without sunlight use basic chemicals to create food. They will oxidize gases like methane (from thermal vents) or hydrogen to gain energy.