Distinguish between

LITHOSHERE – I

ENDOGENETIC PROCESSES

VI. Distinguish between

1. Core and Crust.

Crust

Postition: Outer Layer,

Elements: Silica, Aluminium (SIAL)

Classification: Continental Crust, Oceamic Crust

Thickness: 30 km

Core

Postition: Innermost Layer

Elements: Nickel, Iron (NIFE)

Classification: Inner core (Solid) Outer core (Liquid)

Thickness: 3480 km

2. Epicentre and Hypocentre.

Epicentre

• Epicentre is a point on the Earth's surface that lies directly above the focus.

• The impact of the Earthquake is felt the most at the epicentre.

Hypocentre

• The point of origin of an Earthquake is called Hypocentre (Focus)

• It generates a series of elastic waves.

3. Divergent and convergent boundaries.

Divergent boundaries

• In Divergent boundary the plates pull away from each other as magma pushes up from the mantle

Convergent boundaries.

• In convergent boundaries the plate moves toward each other and some times, a plate sinks under another.

4. Primary waves and Secondary waves.

Primary waves

• The waves pass through solids, liquids, and gases

• The velocity is 5.31 cm per second to 10.6 km per second

• 'P' waves are the fastest of all the Earthquake waves and the first to reach the epicentre.

Secondary waves

• The waves travel only through solids.

• The velocity is 1 km per second to 8 km per second

• These transverse waves shake the ground perpendicular to the direction in which they propagate.

5. Shield volcano and Volcanic Dome.

Shield Volcano:

• Shield volcanoes are formed by intense viscous lava

• These are shallow depositions with gently sloping sides.

• Hence the lava flows out in all directions to create a shield.

E.g. Mauna Loa, Hawaii

Volcanic Dome:

• A lava dome or volcanic dome is roughly a circular mound formed due to the slow ejection of viscous lava from a volcano.

• As the lava is rich in silica with intense viscosity, it is prevented from flowing far from its vent. Eg. Paricutin, Mexico