Earth Science MCQs (Part 21 of 21)

  1. Potential temperature (?) is defined as the temperature of a parcel of dry air at pressure p and temperature T would have if it is expanded or compressed adiabatically to standard pressure ps, usually, 1000 hPa. The expression for (?) is:

    1. ? = T (ps/p) R/Cp

    2. ? = T (p/ps) R/Cp

    3. ? = T (p/ps) Cp/R

    4. ? = T (p/ps) -R/Cp

  2. A convenient measure of the magnitude of the acceleration compared to the Coriolis force may be obtained by forming the ratio of the characteristics scales for the acceleration (U2/L) and the Coriolis force terms (FoU). This nondimensional number, called Rossby Number (Ro), is defined as

    1. Ro = U2/L

    2. Ro = U2/fo. L

    3. Ro = U/fo L

    4. Ro = U/L

  3. The variance (degree of freedom) at known pressure of an eutectic point of the simple binary system as shown in the figure is:

    1. 0 (zero)

    2. Only 1

    3. Only 2

    4. Only 3

  4. Pressure solution Stylolites are observed to be inclined at an angle of 45° relative to the bedding in the rock by a geologist. Which one of the following interpretations is correct?

    1. Styloties cannot be oriented at 45° relative to bedding. The geologist made an error in his observations.

    2. The stylolites are definitely tectonic in region.

    3. The relative angle of stylolites with bedding has no consequence in deciding its origion.

    4. The stylolites are definitely diagenetic in origin.

  5. Overprinting of ductile deformation microstructures by brittle microstructures are observed by a geologist in a thin-section of a deformed rock. Which one of the following interpretations of the observations is false?

    1. The deformation occurred in a brittle-ductile deformation regime.

    2. The deformation occurred in a ductile regime and on-going erosion subsequently changed the deformation regime to brittle.

    3. The deformation regime charged from brittle to ductile due to reduction of grain-size.

    4. The deformation microstructure represents a re-activated fault zone.

  6. The 2006 Sumatra Earthquake produced a tsunami in the southern Bay of Bengal. Potential tsunamigenic region affecting the Arabian sea is

    1. the Kachchh region in Gujarat

    2. the Palaghat region in Kerala

    3. the Makran coastal region in South Pakistan

    4. the Bombay High Region.

  7. Active tectonic studies using Global Positioning System in the Indian Subcontinent indicate that Himalayan seismic hazard is

    1. the highest in regions that have not experienced great earthquakes in the recent past.

    2. the highest in regions that have experienced great earthquakes in the recent past.

    3. lower compared to peninsular India.

    4. same as that of peninsular India.

  8. Himalayan mountains have formed primarily as a result of

    1. compressive deformation between Indian and Asian tectonic plates.

    2. relative uplift of sediments in the Tethys Ocean in an extensional setting

    3. strike-slip deformation between Indian and Eurasian plates.

    4. extrusion of volcanic material over a long period of time on the Tethys ocean floor.

  9. The Carlsberg Ridge in the Indian Ocean is a divergent plate boundary between the Indo-Australian (IA) and African tectonic plates because

    1. the IA plate moves to the NE and the African plate moves SW at the ridge.

    2. both the plates move northwards, but the IA plate moves faster.

    3. both the plates move southwards, but the African plate moves faster.

    4. both the plates move northwards, but the IA plate moves slower.

  10. In convergent plate tectonic setting, thickest continental lithosphere is associated with

    1. Ocean-Ocean convergent settings.

    2. Ocean-Continent convergent settings.

    3. Continent-Continent collision settings

    4. Ocean-Ocean divergent settings.