Question

Describe deep sea trenches and abyssal plains and their relative ages.

Answer 1

Deep sea trenches are relatively young depressions at convergent boundaries, while abyssal plains are flat, sediment-covered areas that are generally older. The seafloor spreading rate of the East Pacific Rise is faster than the mid-Atlantic Ridge, as evidenced by the age of the seafloor and the symmetrical patterns of seafloor age extending from each spreading center.

Step-by-step explanation:

Deep sea trenches and abyssal plains are significant features of the ocean floor, shaped by tectonic activities. Deep sea trenches are long, narrow depressions on the seafloor, typically located at convergent plate boundaries where one tectonic plate is being subducted beneath another. Due to the continued subduction of oceanic plates, trenches are commonly associated with some of the youngest regions of the ocean floor. In contrast, abyssal plains are flat, almost level areas of the deep ocean basin. These plains are among the most extensive flat regions on Earth and are formed by the fine sediments that cover the ocean floor, making them much older than the trenches because the sedimentation process is slow and steady over extensive periods.

The age differences between the seafloor at the mid-Atlantic Ocean and the Pacific Ocean, off the coast of South America, provide insights into the rates at which tectonic plates are spreading. The mid-Atlantic Ridge has a slower spreading rate compared to the East Pacific Rise, a fact discernible by examining the seafloor ages depicted by the Age of Oceans image from NOAA. The pattern of symmetrical seafloor ages on either side of a mid-ocean ridge and the distance from the ridge to the oldest seafloor can be used to compare spreading rates.

Answer 2

Oceanic Trench or Deep Sea Channel, it is a narrow, long and having a sharp inclination depression in the lowermost deep-sea in which happen the extreme oceanic depths. They normally form in places where once the structure of the earth's crust plate is forced below the edge of another. While Abbysal plain is a beneath the surface of the water plain on the deep ocean floor, typically found at depths approximately 3,000 meters and 6,000 meters. It is in a horizontal position largely between in a mid-ocean ridge and a foot of a continental rise. Almost 50% of the Earth’s surface was sheltered by Abbysal Plains. They are the smoothest and flattest and not so discovered areas on Earth.