Title of notes: trenches Pg. 24 & 25 RS

Goal for lesson: (Learning target) I’ll know I’ve got it when… I can draw how a trench is formed. Today I am… Learning about how tectonic plates movement leads to geological features. So that I’ll be able to… understand how our geological features formed on Earth. I’ll know I’ve got it when… I can draw a diagram of a trench and label it correctly.

Trench Trench: a long, narrow, deep depression in the ocean floor, typically one running parallel to a plate boundary and marking a subduction zone. Can be up to 7300+ meters (4.5 miles) deep Form at a convergent boundary: An oceanic – continental plate An oceanic – oceanic plate

Trench CONDITIONS water pressures more than 1,000 times greater than the surface constant temperatures just above freezing no light to sustain photosynthesis Many of the organisms living in trenches have evolved surprising ways to survive in these unique environments

subduction a geophysical process in which two or more of Earth's tectonic plates converge and the older, denser plate is pushed beneath the lighter plate and deep into the mantle, causing the seafloor and outermost crust (the lithosphere) to bend and form a steep, V- shaped depression Subduction also generates an upwelling of molten crust that forms mountain ridges and volcanic islands parallel to the trench. Examples of these volcanic "arcs" can be seen in the Japanese Archipelago, the Aleutian Islands, and many other locations around this area called the Pacific "Ring of Fire."

FIRST STOP IS JAPAN Japan

MARIANA TRENCH Deepest part of the earth 10, 994 meters or 6.8 miles deep (known as the Challenger Deep) Formed by ocean-to- ocean subduction Oceanic – oceanic crust converge and the older crust subducts underneath newer crust. Convergent boundary Located in the Pacific Ocean near Japan

The trench is deep enough that Mt. Everest could fit in its place

Snailfish Ghostfish

Mariana Trench https://www.youtube.com/watch?v=Y2tm40uMhDI

Notebook Activity Pg. 24 LS Create a diagram of a trench and label. Convergent boundary Oceanic crust (plate) older crust Oceanic crust (plate) newer crust Subduction zone