Question

Define the following
(a)plate tectonics
(b)seismology​

Answer 1

Answer:a)

a theory explaining the structure of the earth's crust and many associated phenomena as resulting from the interaction of rigid lithospheric plates which move slowly over the underlying mantle.

b) It  is the scientific study of earthquakes and the propagation of elastic waves through the Earth or through other planet-like bodies. The field also includes studies of earthquake environmental effects such as tsunamis as well as diverse seismic sources such as volcanic, tectonic, oceanic, atmospheric, and artificial processes such as explosions. A related field that uses geology to infer information regarding past earthquakes is paleoseismology.

Explanation:

Answer 2

(in geology) the movements of the large sheets of rock (plates) that form the earth’s surface; the scientific study of these movements.