Section A
Q1.
(a) Compute the geoid height anomaly resulting from an isostatic density distribution (Airy-compensated) of ocean basin 6 km deep.
(b) A 30 Hz seismic signal reflects from the base of a 2 km thick layer with velocity v = 4 km/s. What is the minimum size of horizontal feature that could be detected?
(c)
Draw schematically the gravity and magnetic anomalies over a given two-dimensional body (see the figure below). Explain the salient features on the difference between the two anomalies.
Direction of magnetization in the body is marked by an arrow.
(d) Calculate the angles of refraction for P-wave and S-wave for an incident P-wave undergoing mode conversion.
(e) Sketch the sequence x(n) = 0.5delta(n+1) + 3delta(n-1) + 2delta(n-2).
(f)
An analog signal is given as follows :
xa(t) = 3cos 50pi t + 10sin 300pi t - cos 100pi t
Find the Nyquist rate.
(g) Write briefly the different types of remote sensing methods and explain the importance of electromagnetic radiation in remote sensing studies.
(h) Enumerate the causes and consequences of excess water drawn in coastal aquifers.
