About a Geophysics degree
About
Geophysics is the science of understanding the Earth using the advencements in physics and geology.
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If you like alternating beween the outdoors and a computer lab running elaborate models, then geophysics might just be the degree for you!
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Geophysicist use techniques based of electro-magnetics, gravity and sound waves to understand the subsurface. They are also heavily involved in designing new analytical instruments.
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This degree links theoretical physics, practical physics, geology and fieldwork altogether, making it a very versatile degree. The interest of this discipline is to apply well known physics principles to the complex, open system that is the Earth.
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Geophysics has played a major role in understanding the Earth and finding recources, allowing for intellectual and technologycal advances throughout the last century.
Nowdays, geophysics provides crucial data for many subjects such as climate change, underground water reserve management, water pollutants, storage of pollutants, ressources management, natural disater prediction, innovative technologies, archeological research and more... This field of study is in high demand as we move to a more sustainable future!
Geophysics allows to quantify the subsurface. Put together with geological studies, this allows for accurate probability 3D models of the subsurface. These models are highly sought for in industry and research to answer modern issues.
From field resistivity surveys to a 3D reconstruction of the subsurface
An example of a geophisics subject: gravity surveys
Gravity map of Edinburgh, corrected for topography and lattitude. From Dr David Stevenson
At school, the general consensus is that gravity at the surface of the Earth (at sea level) is of 9.81 m/s , as calculated using the distance to the center of the Earth and the mass of the Earth. But small variations in these parameters will change the measured gravity at the surface. These variations come from changes in topography and latitude.
For topography, an increase elevation increases the distance of the surface to the center of the Earth, reducing the gravity, but at the same time we need to account for the mass of the mountain, increasing gravity. If we avearge these two effects, we end up with a smaller overall gravity on top of a hill than at sea level.
For latitude, 3 elements come at play. The Earth spins and the centrifugal force, stronger closer to the equator, reduces the measured gravity. The spinning of the Earth also affects its shape, making it bulge at the equator. This increases the distance to the center of the Earth as well as locally increasing the amount of rock, thus affecting gravity both ways.
It is possible to correct measurements for topography and latitude, leaving the composition of the subsurface as the only significant factor of gravity variations.
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These are the kind of studies that are conducted in order to better understand what lies beneath our feet, and by studying geophysics you could be a part of it!
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Topics within geophysics
Geophysics allows specifications in different fields:
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Subsurface exploration (on land and at sea) is the documentation of the subsurface for general use, creating an in-depth database. Such data is used in the context of infrastructure construction and academic advancements.
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Athmospheric studies make up for a big section of geophysics as physics is eavily used for the understanding and modelling of athmospheric processes. The movement of air massess impacts the global climate, weather and is necessary in order to fully understand the impact of human emissions.
Hydrogeology studies at the behaviour of water in the ground. One speciality of geophysics is the study of the movement of fluids in the ground. Most of hydrology relies on geophysical models. This ranges from creating sustanable access to groundwater and tracking contaminants, to using the heat of the Earth as geothermal energy.
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Ressource exploration focuses on a range of high resolution surveys that, linked with geological studies, allow to identify and constrain the location of ressources in order to satisfy the ever-growing demand. Materials and energy ressources will allways be necessary, especially for the high-tech required for a sustainable future. As well as locating exploitable ressources, developping inventive ways to extract them in a sustainable way is a major part nowdays.
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Space exploration relies heavily on geophysical techniques and knowledge of geophysicists. All the remote data aquisition practiced on Earth is used on other space bodies. For example, plenty of geophysical equipement is currently used on board of the Mars rovers. If you want to be part of a sci-fi project, this is it!
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Archeology surveys focuses on using remote sensing techniques like gravity, seismic and electromagnetic surveys to identify buried remains of past civilisations.
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It is important to note that cross-overs between geoscience subjects give rise to very intersting discoveries, and it is thus perfectly fine to mix geophysics with another field.
Ground-penetrating radar RIMFAX for Mars exploration rovers,
NASAJPL-Caltech
Diagram of the principles behind a reflexted waves survey
Electromagnetic survey used for archeology. King johns Palace Kings Clipstone Nottinghamshire high pass resistivity geophysics 2010 CC BY-SA 3.0
Additional useful links
Further Geophysics degree information:
Geophysics desciption by environmentalgeoscience.org
Geological society of London Geophysics degree informations
University of Edinburgh Geophysics degree description
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Related careers:
Geological society of London careers information
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Interesting blogs:
The Oldest Magnetic Field? Hunting the Hadean magnetic field