A mid-ocean ridge or mid-oceanic ridge is an underwater mountain range, formed by plate tectonics. This uplifting of the ocean floor occurs when convection currents rise in the mantle beneath the oceanic crust and create magma where two tectonic plates meet at a divergent boundary.
Answer:
1. phytoplankton blooms
Explanation:
- A dead zone is a zone that is created by the presence of the dead and decomposing matter of the plant an abiotic component that depletes the oxygen and thereby creating a thick layer of nutrient-rich deposits in the aquatic environment that does not support the marine and fish life.
- They may result from agricultural, industrial and urban flows. And the changes that occur with the climate changes and the seasonal cycles of the earth. There are four types of dead zones classified on their lengths.
<u>Permanent </u><u>dead zone i.e the rarely exceed 2 milligrams per liter.
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<u>Temporal </u><u>dead zones i.e the short-lived dead zone that lat flour hours a day.
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<u>Seasonal </u><u>dead zones occur annually mostly in the summer months.
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<u>The </u><u>hypoxic </u><u>zone that occurs in the night time.
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The baltic seas, Chesapeake bays, Lake Erie, and the other zone are affected by these blooms of algae and other foreign substances.
Answer: Deep Focus
Explanation:
A Deep focus earthquakes is one that occurs deeper beneath the subduction zone called Wadati-Benioff zone having a focus greater than 300 km deep and magnitudes greater than 6, Because of these, they can only be measured using the Moment Magnitude scale which can measure earthquakes with magnitude over 10
Here there is a forceful collision of the tectonic plates as they slide over each other within the continental and oceanic plates boundaries causing the release of great energy,with extreme heat and pressure causing the rocks to flow instead of breaking and faulting of the rocks
Deep focus earthquakes are very dangerous although occurring 20 - 30 years along a fault line are responsible for the many destructive tsunamis that happen.