Litho-Sphere of Influence (Layers of the Earth)
This brittle, rigid outer layer of the Earth is composed of both the crust and the uppermost layer of the mantle.
What is the lithosphere?
This is the specific type of crustal boundary where plates smash together, forcing one downgoing sheet to sink underneath the other.
What is a convergent boundary?
This famous, isolated Pacific paradise stands as the ultimate textbook example of hot-spot volcanism.
What are the Hawaiian Islands?
This is the massive, soaring mountain range that buckled upwards when India slammed headfirst into Asia.
What are the Himalayas?
If you plot global seismic activity data on a blank map, these explosive shaking events will trace out lines that point directly to these borders.
What are plate boundaries?
Unlike the rigid sheet above it, this hot, soft layer of the mantle is plastic enough to flow slowly over vast spans of time.
What is the asthenosphere?
This is the structural reason why oceanic lithosphere subducts easily into the mantle, while continental lithosphere refuses to sink.
What is oceanic crust is denser/less buoyant?
Hot spots don't move around; they are caused by these stationary, column-like upwellings of intense heat rising from deep mantle realms.
What are mantle plumes?
This structural process occurs when continental lithosphere stretches, thins, breaks along normal faults, and generates fresh volcanic lines.
What is continental rifting?
This specific type of plate motion calculation measures the speed of one tectonic plate compared directly to its immediate neighbor plate.
What is relative plate velocity?
When comparing a block of continental lithosphere to a block of oceanic lithosphere, the continental block is significantly distinct in this parameter.
What is thicker? (Accept: less dense)
This distinct, linear seismic belt of earthquakes maps out the exact angle and depth of an oceanic slab diving 660 km deep into the earth.
What is the Wadati-Benioff zone?
If you trace a linear hot-spot track across a moving plate, you will find that the islands or seamounts progress in this specific fashion with distance from the hotspot.
What is they increase in age? (Accept: They get older.)
The dramatic Basin and Range Province in the western United States stands out as a prime active example of this structural tectonic event.
What is a continental rift?
This type of calculation tracks a plate's speed relative to a fixed, stationary point deep inside the Earth's interior (like a mantle plume).
What is absolute plate velocity?
When a heavy geological load like an ice sheet or island volcano sits on Earth's surface, the rigid lithosphere reacts by doing this.
What is bending?
When a subducting slab drags sea-floor sediments down into a trench, the overriding plate acts like a scraper, building this wedge-shaped rock mass.
What is an accretionary prism?
Over vast expanses of time, hot-spot volcanic islands erode down and subside completely below sea level, forming flat-topped seamounts called this.
What are guyots?
When an ocean basin closes entirely and two buoyant landmasses fuse together, they leave behind this deep, highly compressed structural scar line.
What is a suture?
This force kicks into gear when high, hot topography along mid-ocean ridge slopes pushes outward under the relentless pull of gravity.
What is ridge push?
Convection currents are fascinating, but modern geologists recognize that these internal cells are no longer thought to act as this.
What is the sole driver of plate motion?
When subduction involves two oceanic plates colliding, a curved chain of volcanoes pops up on the overriding plate to form this structural feature.
What is a volcanic island arc?
Hot spots show zero favoritism; they can burn open active volcanic paths through both oceanic lithosphere and this alternative layer.
What is continental lithosphere? (Accept: continental crust / continental plates)
Long before it became a narrow ocean basin with an active mid-ocean ridge, this modern body of water started out as a simple continental rift Valley.
What is the Red Sea?
Widely considered the most powerful driving force in plate tectonics, this occurs because cold, old oceanic slabs are denser than the warm mantle beneath them.
What is slab pull?