processes at tectonic boundaries

Faulting

Stress builds up as plates push, pull, or slide; Rocks bend and deform; Rocks crack → fault forms; Energy is relased→ rocks slip; Earthquakes occur

Continental - Continental divergent

magma rises beneath the continent, causing it to become thinner, break, and ultimately break apart. New ocean crust erupts creating an ocean between continents. A divergent plate boundary on land rips apart continents.

Rift Volcanoes

form when magma rises into the gap between diverging plates.

Oceanic - Oceanic divergent

Volcanic eruptions at the bottom of the sea occur as the oceanic crust splits apart. Ocean floor becomes wider due to SEAFLOOR SPREADING

Harry Hess

1960, created the theory of seafloor spreading.

Sea - Floor spreading

The process that continually adds new material to the ocean floor while pushing older rocks away from the ridge

Mid - Ocean Ridge

Is an underwater mountain range, formed by plate tectonics.

Underwater Rift valleys

Are points where hot molten rock rises and turn into mid ocean ridge.

Convergent (Destructive)

The two plates push into each other.

Oceanic - oceanic convergence

When subduction occurs, a chain of volcanoes often develops near the convergent plate boundary.

Subduction

A process when one of the two plates is descending beneath the other; an older, denser tectonic plate being forced deep into the planet underneath a younger, less-dense tectonic plate.

Oceanic - continental convergence

The result of this subduction is a mountain range, with many volcanoes; It produces a trench and a volcanic arc, series of volcanic eruptions along the edge of continental plate can be observed.

Continental - Continental convergence (Collision)

When two continental plates converge, they cannot submerge into the mantle due to their composition. This lack of subduction leads to the plates crumpling upwards, forming fold mountains like Himalayas; this event can result in shallow-focus earthquakes, but it does not lead to volcanic activitu, as no magma is a involved.

Slab pull

Is the force exerted by a sinking tectonic plate as it is pulled into the mantle at a subduction zone; is like dragging heavy rug into hole-once part of it falls, the rest is pulled down automatically; An oceanic plate becomes dense as it cools over time; When it reaches a subduction zone, it starts to sink beneath a lighter plate; Gravity pulls the rest of the plate along into the mantle;

Ridge Push

At divergent boundary, magma rises to form new oceanic crust; This new crust is hot and elevated, forming a mid-ocean ridge; Gravity causes the elevated ridge to slide down, pushing the older crust outward; the force that occurs at mid-ocean ridges where new crust forms and pushes older crust away; helps drive plates apart at divergent boundaries, creating space for seafloor spreading