Tectonic Plates

Plate Tectonic theory- is the theory that Earth’s outer layer

is made up of plates.- the rocky inner layer above the

floor. - from the 1950’s through the 1970’s,

plate tectonics is the modern version of continental drift.

- German climatologist and geophysicist who, in 1915, published as expanded version of his 1912 book The Origin of Continents and Oceans.

- He suggested that all the major continents formed one giant supercontinent, called PANGEA.

- 200 million years ago, PANGEA began to rift.

- Oceans filled the areas between these new sub-continents.

- The land masses continued to move apart, riding on separate plates, until they reached the positions they currently occupy.

- What drives plate tectonics? NOT KNOWN.

- One theory said that convection within the Earth's mantle pushes the plates;

- in much the same way that air heated by your body rises upward and is deflected sideways when it reaches the ceiling.

- Another theory is that gravity is pulling the older, colder, and thus heavier ocean floor with more force than the newer, lighter seafloor.

Plate Boundaries

- the region where plate meet. The plates may either collide, move away from each other or slip/slide past each other

Four types of boundaries- Divergent

Boundaries- Convergent

Boundaries- Collisional

Boundaries- Transform

Boundaries

Divergent Boundaries- Where new crust

is formed.- Hot mantle rock

rises and partial melting occurs.

Convergent Boundaries- Where crust is

consumed.- One subducts beneath

the other, and in the process a trench is formed.

- Where two land masses collide.

- The two crush together.

Collisional Boundaries

- Where two plates slides against each other.

transform Boundaries

Philippine Sea PlateMariana PlatePhilippine Sea Plate

The Mariana Plate is a small tectonic plate located west of the Mariana Trench and forms the basement of the Mariana Islands. It is separated from the Philippine Sea Plate by a long divergent boundary with numerous transform fault offsets. The boundary between the Mariana and the Pacific Plate to the east is a subduction zone with the Pacific Plate subducting beneath the Mariana. The Mariana Trench forms the southeastern boundary and the Izu-Ogasawara Trench the northeastern boundary.

Mariana Plate

Type Minor

Approx. Area 360,000 km2[1]

Movement1 north-west

Speed139-51mm/year

FeaturesMariana Islands, Mariana Trench

o The Philippine Mobile Belt is a complex portion of the tectonic boundary between the Eurasian Plate and the Philippine Sea Plate, comprising most of the country of the Philippines.

o It includes two subduction zones, the Manila Trench to the west and the Philippine Trench to the east, as well as the Philippine Fault System.

o Within the Belt, a number of crustal blocks or microplates which have been sheared off the adjoining major plates are undergoing massive deformation.

Philippine Sea Plate

Philippine Sea PlateType MinorApprox. Area 5,500,000 km2

Movement1 north-westSpeed1 48-84mm/year

Features Philippines, Philippine Sea