Daily Static Quiz March 8, 2025
Daily Static Quiz
Question 1: Consider the following statements regarding the composition of Earth’s mantle and outer core:
1. The mantle is primarily composed of silicon and magnesium
2. The outer core is in a solid state
3. The outer core is predominantly composed of nickel and iron
4. The mantle extends from Moho’s discontinuity to a depth of 2,900 km
Which of the statements given above are correct?
(a) 1, 3 and 4 only
(b) 2, 3 and 4 only
(c) 1 and 4 only
(d) 1, 2, 3 and 4
Question 2: Which of the following discontinuities is correctly matched with its location in Earth’s structure?
(a) Mohorovicic discontinuity – Between upper mantle and lower mantle
(b) Gutenberg discontinuity – Between inner mantle and upper core
(c) Lehmann discontinuity – Between lower mantle and outer core
(d) Conrad discontinuity – Between inner core and outer core
Question 3: With reference to seismic waves, consider the following statements:
1. P-waves can travel through solids, liquids, and gases
2. S-waves travel faster than P-waves
3. The velocity of P-waves in the Earth’s crust is less than 6 km/s
4. S-waves can penetrate through the Earth’s outer core
Which of the statements given above are correct?
(a) 1 and 3 only
(b) 2 and 4 only
(c) 1, 2 and 3 only
(d) 3 and 4 only
Question 4: Which of the following is primarily responsible for generating Earth’s magnetic field?
(a) Movement of charged particles in the ionosphere
(b) Rotation of solid inner core
(c) Movement of molten iron in the outer core
(d) Interaction between the crust and upper mantle
Question 5: Which of the following is NOT a component of Earth’s magnetosphere?
(a) Van Allen Radiation Belts
(b) Magnetopause
(c) Plasmasphere
(d) Asthenosphere
Question 6: What is the heliopause?
(a) The region where Earth’s magnetic field meets the Sun’s magnetic field
(b) The boundary of the heliosphere where solar magnetic fields and solar wind end
(c) The layer between Earth’s stratosphere and thermosphere
(d) The zone where solar radiation is converted to heat in Earth’s atmosphere
Question 7: Aurora Borealis (Northern Lights) and Aurora Australis (Southern Lights) are primarily caused by:
(a) Reflection of sunlight from ice crystals in polar stratospheric clouds
(b) Interaction of solar wind particles with Earth’s magnetic field and atmosphere
(c) Bioluminescence from marine organisms in cold polar waters
(d) Refraction of moonlight through water vapor in polar regions
Question 8: With reference to the Earth’s mantle and asthenosphere, consider the following statements:
The asthenosphere is the upper portion of the mantle
The asthenosphere is completely solid
The mantle extends from Moho’s discontinuity to a depth of 2,900 km
The mantle is primarily composed of silicon and magnesium
Which of the statements given above are correct?
(a) 1, 3 and 4 only
(b) 2, 3 and 4 only
(c) 1 and 2 only
(d) 1, 2, 3 and 4
Question 9: Which of the following statements correctly describes surface seismic waves?
(a) They travel through the Earth’s inner core and are the fastest seismic waves
(b) They are generated only in deep-focus earthquakes occurring below 300 km
(c) They travel along the Earth’s surface and cause the most destruction during earthquakes
(d) They can only travel through solid materials and not through air or water
Question 10: Which of the following North Pacific Ocean trenches is correctly matched with its associated tectonic plates?
(a) Mariana Trench – Pacific Plate subducting beneath the Philippine Sea Plate
(b) Japan Trench – Philippine Sea Plate subducting beneath the Eurasian Plate
(c) Aleutian Trench – North American Plate subducting beneath the Pacific Plate
(d) Kuril-Kamchatka Trench – Eurasian Plate subducting beneath the Pacific Plate
Answers with Explanations
Answer 1: (a) 1, 3 and 4 only
Explanation:
Statement 1 is correct. The major constituent elements of the mantle are Silicon and Magnesium, which is why it is often termed as SIMA. Statement 2 is incorrect. Unlike the mantle which is in a solid state, the outer core is in a liquid state while the inner core is solid. Statement 3 is correct. The core (including both outer and inner parts) is primarily composed of nickel and iron, hence it is called the “nife” layer. Statement 4 is correct. The mantle extends from Moho’s discontinuity to a depth of 2,900 km, where it meets the core-mantle boundary.
Answer 2: (b) Gutenberg discontinuity – Between inner mantle and upper core
Explanation:
The correct pairings of discontinuities and their locations are: Mohorovicic (Moho) discontinuity separates the crust and upper mantle, not upper and lower mantle. Conrad discontinuity separates the upper and lower crust, not the inner and outer core. Gutenberg discontinuity separates inner mantle and upper core, which makes option (b) correct. Lehmann discontinuity separates the upper core and lower core (or outer core and inner core), not the lower mantle and outer core.
Answer 3: (a) 1 and 3 only
Explanation:
Statement 1 is correct. P-waves or Primary waves can travel through all mediums – solids, liquids, and gases. Statement 2 is incorrect. P-waves are the fastest among seismic waves (hence called “Primary”) and are recorded first on seismographs. Statement 3 is correct. The precise speed of P-waves varies according to the region of the Earth’s interior, with less than 6 km/s in the Earth’s crust. Statement 4 is incorrect. S-waves do not travel through liquids as they are attenuated in liquid media. Since the outer core is liquid, S-waves cannot penetrate through it, which is why there is a shadow zone of S-waves beyond 103° from the epicenter.
Answer 4: (c) Movement of molten iron in the outer core
Explanation:
Earth’s magnetic field is generated in the Earth’s outer core. The lower pressure than the inner core means the metal in the outer core is fluid. This fluid motion of electrically conductive material (primarily molten iron) in the outer core creates a dynamo effect that generates and maintains Earth’s magnetic field. This mechanism is known as the geodynamo. The movement of this conductive fluid creates electric currents, which in turn produce magnetic fields.
Answer 5: (d) Asthenosphere
Explanation:
The magnetosphere consists of several distinct regions including the Magnetosheath (the outer boundary where solar wind compresses the magnetosphere), Bow Shock (where solar wind collides with the magnetosphere), Magnetopause (the inner boundary marking where Earth’s magnetic field balances with solar wind pressure), Plasmasphere (region filled with low-energy charged particles), and the Van Allen Radiation Belts (donut-shaped regions containing high-energy charged particles). The asthenosphere is not part of the magnetosphere but is instead the upper portion of Earth’s mantle that exhibits plastic properties.
Answer 6: (b) The boundary of the heliosphere where solar magnetic fields and solar wind end
Explanation:
The heliopause is defined as the boundary of the heliosphere, which is the spherical region around the Sun that is filled with solar magnetic fields and the outward-moving solar wind consisting of protons and electrons. It marks the outer limit of the Sun’s influence, where the pressure of the solar wind balances with the pressure of interstellar space. Beyond the heliopause, the interstellar medium (ISM) dominates. Nearer the Sun than the heliopause lies the heliosheath, a region of transition where the solar wind slows to subsonic speeds.
Answer 7: (b) Interaction of solar wind particles with Earth’s magnetic field and atmosphere
Explanation:
Auroras occur when charged particles from the Sun (primarily electrons and protons) are guided by Earth’s magnetic field toward the poles. When these energetic particles collide with atoms and molecules in Earth’s upper atmosphere (mainly oxygen and nitrogen), they transfer energy to these atmospheric gases. As the energized atmospheric atoms return to their normal state, they release photons of light, creating the colorful displays we know as auroras. The Aurora Borealis appears in the northern hemisphere, while the Aurora Australis occurs in the southern hemisphere. The Earth’s magnetosphere plays a crucial role in directing these charged particles toward the polar regions along magnetic field lines.
Answer 8: (a) 1, 3 and 4 only
Explanation:
Statement 1 is correct. The asthenosphere is the upper portion of the mantle. Statement 2 is incorrect. While the mantle as a whole is generally in a solid state, the asthenosphere specifically exhibits plastic properties, allowing it to flow slowly. It is the chief source of magma that finds its way to the surface during volcanic eruptions. Statement 3 is correct. The mantle extends from Moho’s discontinuity to a depth of 2,900 km, where it meets the core-mantle boundary. Statement 4 is correct. The major constituent elements of the mantle are Silicon and Magnesium, which is why it is often termed as SIMA.
Answer 9: (c) They travel along the Earth’s surface and cause the most destruction during earthquakes
Explanation:
Surface seismic waves, as their name implies, travel along the Earth’s surface rather than through its interior. There are two main types of surface waves: Love waves and Rayleigh waves. Surface waves are typically the most destructive seismic waves during earthquakes because they have larger amplitudes, longer periods, and lower frequencies than body waves (P-waves and S-waves). They arrive after the P and S waves but can cause significant horizontal and vertical ground movement. Love waves move the ground from side to side, while Rayleigh waves create an elliptical motion similar to ocean waves. Surface waves attenuate more slowly with distance than body waves, allowing them to cause damage at greater distances from the epicenter.
Answer 10: (a) Mariana Trench – Pacific Plate subducting beneath the Philippine Sea Plate
Explanation:
The Mariana Trench is formed at the convergent boundary where the Pacific Plate subducts beneath the Philippine Sea Plate, which is correctly stated in option (a). The Japan Trench is actually formed by the subduction of the Pacific Plate beneath the Okhotsk Plate (part of the North American Plate), not the Philippine Sea Plate beneath the Eurasian Plate. The Aleutian Trench is formed by the Pacific Plate subducting beneath the North American Plate, not the other way around as stated in option (c). Similarly, the Kuril-Kamchatka Trench is formed by the Pacific Plate subducting beneath the Okhotsk Plate (part of the North American Plate), not the Eurasian Plate subducting beneath the Pacific Plate. Oceanic trenches are typically formed where oceanic lithosphere is subducting beneath either continental lithosphere or other oceanic lithosphere, creating deep depressions along the subduction zones.
