GeologyRocks

Plate Tectonics: The Evidence

The evidence for plate tectonics comes many fields, such as palaeontology, geophysics and climate study. The first evidence was the matching of continents and their rock types across oceans. This had been realised since the 17th Century. Theories of how continents moved were ad hoc at best. Alfred Wagner, an early 1900's German Meteorologist proposed that the continents of South America, Africa, India and Australia had been one continent in the past due to their similarity of fossils and palaeoclimate.

Meteor Craters

A meteorite is defined as any extraterrestrial solid mass that reaches the Earth's surface (Farris Lapidus, 1990). The term strictly extends from the nano scale e.g. dust particles, through to the macro scale e.g. 100s of metres in diameter (Zanda and Rotaru, 2001). However, the term meteorite is generally reserved for the larger particles that reach the Earth's surface.

Programming Fortran 2

This is a continuation of Fortran 1. This tutorial might not make much sense unless you have read that first.

Writing and Reading from Files, Screens and Keyboards

Fortran is capable of reading data from files and from the keyboard. It can also write data to files and to the screen. The I/O (Input-Output) in Fortran is a little cumbersome and is not very flexible, but is easy to get the hang of.

Programming Fortran 1

This tutorial is designed for those who have to learn Fortran. Not that Fortran is a bad language to learn and it is used extensively throughout the scientific community. However, it is often the first programming language scientists encounter, so this tutorial designed to give you the basics of the language, without (hopefully) the use of complicated paradigms or ideas.

Gravity Surveying

Gravity surveying involves looking at the subsurface structure based on the differences in densities of the subsurface rocks. The idea is based around a causative body - one which produces a gravity anomaly. Assessment of gravity anomalies can give ideas about depth, size and shape of the causing body. Gravity anomalies are measured in ms^-2. As the anomalies are very small compared to the Earth's field (9.81ms^-2), they are commonly expressed in gravity units (g.u.), where 1 gu = 1μms^-2.

Plate Tectonics: An Introduction

Plate tectonics is the theory that underpins most of modern geology. The basic idea is that the surface of the Earth is made up of several segments - plates. These plates move around the globe while being created and destroyed at their margis. This theory helps to explain many things, such as the rock types that indicate desert climates in north England. Rather than have to move the climatic belts, it is the continent itself that has moved.