Interior of the Earth

Question 1

All natural EQs take place in?

Answer 1

Lithosphere

Question 2

About P, S, L waves

Answer 2

1. Speed comparison: P > S > L
2. Only waves moving along the wave: P - waves
3. S & L waves can travel only through Solid, whereas P waves travel through Solid, Liquid, Gas
4. Speed of P - waves: S > L > G (Different media)
5. Shadow Zone (S): +105° to -105° and
   Shadow Zone (P): +105° to +142° and -105° to -142°

Question 3

Types of EQs

Answer 3

Remember: TV Cinema Easy Route

1. Tectonic EQ
2. Volcanic EQ
3. Collapse EQ
4. Explosive EQ
5. Reservoir Induced EQ

Question 4

Tsunamis are waves generated by ______ but not an ______ in itself

Answer 4

Tremors and EQ

Primary reason for Tsunami: EQ
Secondary reason for Tsunami: Tremors

Note: Tsunamis can even occur due to Volcanic eruptions, Submarine landslides, etc

Question 5

Facts about Earth’s Interior

Answer 5

1. Almost all layers are Solid, however Asthenosphere (Weak - Semi Solid like Toothpaste) and Outer Core (Liquid)
2. Asthenosphere - Upper layer of Mantle extending upto 400 Km
3. Lithosphere - Crust + Upper most part of Mantle (upto 200 Km)

Question 6

Density value at surface, at centre, and average

Answer 6

At surface ρ = 2.7 g/cm³
Average ρ = 5.5 g/cm³
At center ρ = 13 g/cm³

Question 7

Discontinuities of interior of Earth

Answer 7

Remember: CMR Given Lavishly

1. Outer Crust - Inner Crust: Conrad
2. Inner Crust - Outer Mantle: Moho
3. Outer Mantle - Inner Mantle: Repetti
4. Inner Mantle - Outer Core: Gutenberg
5. Outer Core - Inner Core: Lehmann

Note: Bullen Discontinuity lies within the core differentiating based upon the density between Liquid Core and Solid Core

Question 8

Materials that reach ground from a Volcano

Answer 8

1. Lava Flows
2. Pyroclastic Debris
3. Volcanic Bombs
4. Ash and Dust
5. Gases such as N & S - compounds, H2, Cl, Ar

Question 9

Type of Volcano - Shield Volcano

Answer 9

1. Low Viscosity → Free Basalt Flow (Mostly Basalt only)
2. Largest type of volcanoes
3. Generally, non - explosive
4. Examples: Mauna Loa and Mauna Kea (Largest Volcano: Mauna Loa)

Question 10

Type of Volcano - Stratovolcanoes (or) Composite Volcanoes

Answer 10

1. High Viscosity → Thick Lava Flow
2. Caldera is part of Stratovolcanoes
3. Most explosive
4. Examples: Mt Stromboli (Light house of Mediterranean), Mt Vesuvius, Krakatoa, and Mt Fuji

Question 11

Type of Volcanoes - Flood Basalt Volcanoes

Answer 11

1. Least viscosity → Lava flows like River
2. Fissure type of Volcanoes
3. Examples: Siberian Traps, Deccan Traps, Snake Basin, Icelandic Shield, and Canadian Shield

Question 12

Type of Volcano - Cinder Cone

Answer 12

1. Releases only Pyroclastic products
2. Generally found in NW America

Question 13

Active Volcanoes are?

Answer 13

Stromboli, Krakatoa, Vesuvius, Etna, and Barren Island (A&N Islands)

Question 14

Dormant Volcanoes Example

Answer 14

Mt Kilimanjaro

Question 15

Extinct Volcanoes

Answer 15

Mt Kenya → In general, any volcano before going extinct releases fumaroles or solfataras

Question 16

Basic Volcanoes

Answer 16

1. Rich in Fe and Mg (Mafic)
2. Less Viscous and Less Explosive
3. Dark Color
4. High Temperature

Question 17

Acidic Volcanoes

Answer 17

1. Rich in Silica
2. High Viscous and High Explosive
3. Light Color
4. Low Temperature