Ocean Trenches

Read this passage about the ocean trenches and answer the questions below. Ocean trenches are long, narrowdepressions on theseafloor. Thesechasms are the deepest parts of the ocean—and some of the deepest natural spots on Earth. Ocean trenches are found in every oceanbasinon the planet, although the deepest ocean trenches ring the Pacific as part of the so-called “Ring of Fire” that also includesactive volcanoes andearthquakezones.Ocean trenches are a result oftectonic activity, which describes the movement of the Earth’slithosphere. In particular, ocean trenches are a feature of convergent plate boundaries, where two or moretectonic plates meet. At many convergent plate boundaries,denselithosphere melts or slides beneath less-dense lithosphere in a process calledsubduction, creating a trench.Ocean trenches occupy the deepest layer of the ocean, the hadalpelagic zone. The intense pressure, lack of sunlight, and frigid temperatures of the hadalpelagic zone make ocean trenches some of the most unique habitats on Earth. Ocean trenches Long narrow depression in the sea floor Trenches are formed by? (basic explanation) Tectonic activity Deepest trenches located Pacific "Ring of Fire" Convergent plate boundaries Where tectonic plates meet Subduction Dense lithosphere melts or slides beneath less-dense lithosphere Hadalpelagic zone Deepest layer of the ocean Habitat description Intense pressure, lack of sunlight, and frigid temperatures Creatures of the Deep Watch the video and answer the following questions. Read this text about life in the trenches. Ocean trenches are some of the most hostile habitats on Earth. Pressure is more than 1,000 times that on the surface, and the water temperature is just above freezing. Perhaps most importantly, no sunlight penetrates the deepest ocean trenches, making photosynthesis impossible.Organisms that live in ocean trenches have evolved with unusual adaptations to thrive in these cold, dark canyons. Their behavior is a test of the so-called “visual interaction hypothesis,” which states that the greater an organism’s visibility, the more energy it must expend to catch prey or repel predators. In general, life in dark ocean trenches is isolated and slow-moving. Is there any sunlight that penetrates the trenches? Yes No Since there is no sunlight, which process is notable to take place? Chemosynthesis Photosynthesis Pneumonoultramicroscopicsilicovolcanoconiosis Floccinaucinihilipilification Matching Match the correct pairs together. Pressure 1000 times that of the surface Temperature Just above freezing Life in the depths is... isolated and slow moving Read this text about food sources in the deep. Without photosynthesis, marine communities rely primarily on two unusual sources for nutrients.The first is “marine snow.” Marine snow is the continual fall oforganicmaterial from higher in thewater column. Marine snow is mostlydetritus, includingexcrementand the remains of dead organisms such asseaweedor fish. This nutrient-rich marine snow feeds such animals as sea cucumbers and vampire squid.Another source of nutrients for ocean-trench food webs comes not from photosynthesis, but from chemosynthesis. Chemosynthesis is the process in which producers in the ocean trench, such as bacteria, convert chemical compounds into organic nutrients. The chemical compounds used in chemosynthesis are methane or carbon dioxide ejected from hydrothermal vents and cold seeps, which spew these toxic, hot gases and fluids into the frigid ocean water. One common animal that relies on chemosynthetic bacteria for food is the giant tube worm. What are the two sources of nutrients in the depths? Marine snow Converting sunlight into energy Converting chemical compounds into organic nutrients Matching Match the correct pairs together. Detritus Excrement and dead organism remains Chemosynthesis Done by bacterial producers Tube worm food Chemosynthetic bacteria Methane or carbon dioxide These are chemical compounds used for chemosynthesis Label the trench. Trench