BASE GEOPHYSICS

Concept of Gravity Anomaly  Gravity anomaly can be defined as the differences  between the corrected measured gravity and the theoretical (normal) gravity. In most cases gravity anomaly reading is given in milliGal (mGal). As the definition above describes, there are two terms you must understand related to the gravity anomaly such that normal gravity and the observed gravity . Then these terms are described here below in order to get basic insight on this topic. - Normal (theoretical) gravity This is the value of gravity computed without any geological complication. It is computed by the normal gravity formula of the Geodetic reference system. - Observed gravity This is the gravity reading observed at each gravity station after correction have been made for drift and tides. Factors affecting gravity anomaly - Dimensions When we are talking about the dimension of a body we simply mean the size. As the size of the body increases, the probability of producing great gravity att...

When the shaking of the Earth's ground (known as earthquake) occurs at several times, then it is due to release and movement of energetic waves called seismic waves. Without ruining time,. I don't want to dig deeper on this topic, but just give you the basics regarding these waves. Stay alerted! Seismology is the study of seismic waves and Earthquakes. This may include the study of vibration, propagation, types and application of these seismic waves through the Earth. The term seismology originated from two Greek words " Seismos " means Earthquake and " Logos " means study of. The study of these waves is important as it gives clues regarding, ➔ It used to study the structure and nature of Earth's interior. ➔ It is used in seismic exploration geophysics. Note: The main source of seismic waves in nature is produced from Earthquakes. However there are man made sources of seismic waves such as dynamites, Vibrators forexample vibroseis. Although due to heter...

Some phenomena like Earthquakes and volcanic eruptions gives us important facts for understanding Earth's dynamics. The Earth have passed through various geological processes over time that shapes amaizing features you can observe out there such as mountains, oceanic basins, just to mention a few. Although these processes have to interact effectively in a way that can be explained through Plate tectonic theory. PLATE TECTONIC MODEL This involves the formation of new lithosphere at the ridge and its destruction at a subduction zones. The theory explained how the Earth is active (dynamic). It proposed by 1960's . Most of geologists accept plate tectonic theory because it ties together many unrelated geologic features and natural phenomena. Also it is through plate boundaries where some phenomenon such as Mountain building, Earthquake , Volcanic eruptions occurs. There are major seven (7) Tectonic plates known, Africa , North America , South America , Pacific , Eurasian , Antarcti...

Geothermics is the study of the Earth's heat within its interior. The term " geothermics" derived from two greek words, " Geo " means Earth and " therm " means heat or thermal energy. Hence geothermics simply deals with Earth's heat. Earth's internal heat play an important role which inturn control internal terrestrial processes such as i/ Generation of geomagnetic field ii/ Motion of global lithospheric plates. Sources of Internal Earth's heat . The Earth derived its internal heat from the following major sources 1. Radioactive Decay This is regarded as the main source of Earth  internal heat as a results of disentigration of long lived radioactive isotopes. Heat from this source is regarded to power most of geodynamic processes. Since radioisotopes such as Uranium (U) , Thorium (Th) presents in granite and pegmatites rocks in form of uraninite and uranothorite minerals respectively. 2. Cooling of the Earth This includes the heat remai...