20434 Introduction to Geophysics
Credits: 3 intermediate credits in Geology or in Physics
Recommended: Fundamentals of Physics II
Author: Avihu Ginzburg
Objectives: Geophysics deals with the application of physical methods to the study of the solid earth, its internal structure and the processes within it. The majority of geophysical measurements are performed using seismic, electrical, magnetic and other methods on the surface of the earth or above it, and on constructing models of the earth’s deep layers. The course provides basic understanding of these methods and of the earth’s dynamic processes.
Topics: Introduction – what is Geophysics? A general overview of the earth’s shape and internal structure, and the sources of the data; an overview of geophysical processes in the earth and their importance; The earth’s gravitational field – the form of the earth, the gravity field, gravity measurements, the gravimetric anomaly: its importance and modes of interpretation, global changes in the gravity field, isostasy; Magnetism – the earth’s magnetic field, measuring the magnetic field, the magnetic anomaly – importance and interpretation, magnetic anomalies on land and at the bottom of the sea, residual magnetism, the source of the magnetic field, field reversals, the importance of residual magnetism to modern geodynamics and to structural geology; Seismology – seismic waves, wave reflection and refraction; Earthquakes – source and mechanism, locating earthquake epicenters, distribution of earthquake epicenters on the earth, the motion of seismic waves inside the earth and on the surface, structure of the earth’s interior; Applied seismology – study of the earth’s crust using seismic sources; field measurements, data processing and interpretation; rupture and refraction methods; Geodynamics and plate tectonics – the earth’s temperature: measurement, conduction, sources; plate movement, kinds of boundaries and their characteristics.