Bio test part 2

Buoyancy

is an upward force exerted by a fluid (like water or air) on any object placed inside it

How does Buoyancy articulate how it applies to plate tectonics

through a process called isostasy, which describes how the Earth's lithospheric plates float on the semi-fluid asthenosphere underneath them.

tectonic plates

massive, irregular slabs of solid rock that make up Earth's outermost shell and glide slowly over the mantle

plate boundaries

the bordering edge or line where two of Earth's massive tectonic plates meet and interact

-Assess how the distribution of major earthquakes and volcanic arcs relate to plates/plate
Assess how the distribution of major earthquakes and volcanic arcs relate to plates/plate boundaries

Major earthquakes and volcanic arcs are concentrated in narrow belts along tectonic plate boundaries, matching where Earth's moving crustal plates interact

active margins

a coastal region where the boundary between a continent and the ocean acts as an active tectonic plate boundary, leading to frequent earthquakes, volcanic eruptions, and mountain-building.

passive margins

is the transition boundary between continental crust and oceanic crust that is not an active plate boundary.

Identify whether a margin is active or
passive (if supplied with relevant information)

active margins have tectonic actvity (earthquakes, volcanoes, etc)

← → what type of plate boundary is this

divert

arrow going down,

convert

arrow going down and up

transform plate boundaries

Discuss how melting typically occurs in the mantle: what are the processes and the physical
principles behind them (e.g., does the solid/liquid transition depend only on temperature?),

does not happen simply because the rock gets hotter. Because the mantle is solid rock under immense pressure, the solid-to-liquid transition depends on a combination of temperature, pressure, and chemical composition.

In a perfectly dry environment, rock melts when its temperature crosses its solidus—the threshold temperature where rock begins to melt. In the mantle, this transition is driven by three primary physical processes.

Where does the melting typically occur

three specific geographic and tectonic settings on Earth: mid-ocean ridges, subduction zones, and hotspots (mantle plumes).

Mid-Ocean Ridges (Decompression Melting)

This is where the vast majority of Earth's magma is created. It occurs along massive underwater mountain ranges where the Earth's tectonic plates are pulling apart (divergent boundaries).

Subduction Zones (Flux Melting)

This occurs where an oceanic plate collides with another plate and sinks down into the mantle (convergent boundaries).

Hotspots & Mantle Plumes (Thermal & Decompression Melting)

This occurs isolated in the middle of tectonic plates, completely independent of plate boundaries.

How does subduction happen

one tectonic plate moves under another and sinks into the Earth's mantle at a convergent boundary

where does subduction offucur

convergent plate boundaries

why are subduction zones associated with volcanic arcs?

water squeezed from the descending tectonic plate lowers the melting point of the hot mantle above it, causing magma to rise in a curving line parallel to the trench

-Name the two mechanisms that can cause plates to move

slab pull and ridge pull

slab pull

the pulling force exerted by a cold, dense tectonic plate as it sinks into the Earth's mantle under its own weighr

ridge pull

a gravitational force that causes hot, raised oceanic crust at mid-ocean ridges to slide downward and outward, helping to move tectonic plates apart

Describe approximately how many major plates exist on Earth

7

Discuss hot spots; using plate tectonic theory,

is an intense, localized heat source deep within the Earth's mantle that produces a stationary column of melting rock called a mantle plume

illustrate how a hot spot can produce an island
chain or chain of volcanoes on land

Deduce the formation mechanism of a line of volcanoes (given appropriate characteristics)

analyze tectonic setting, age progression, and magma chemistry. Linear volcanic chains are primarily created by three distinct geological mechanisms

If an oceanic and a continental plate meet at a convergent boundary, which will be subducted?

Oceanic plate

Which of the following features is the most common type of divergent plate boundary?

Mid-ocean ridge

Which of the following is a way that material is commonly melted in Earth?

flux melting

Which of the following would not have subduction?

continental-continental boundary

Where would decompression melting be most likely to occur?

divergent boundary