Geophysics
The physical science of Earth and planetary processes
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The field also covers the oceans, atmosphere, cryosphere, and planetary interactions.[1] Using quantitative and observational approaches, geophysics is a physical science that investigates Earth's processes, properties, and its surrounding space environment.[1] The discipline studies Earth's shape, gravitational, magnetic, and electromagnetic fields, along with internal composition, structure, and dynamics as expressed through tectonics, volcanism, and rock formation.[1]
Quick Facts
- Field
- Physical science
Facts from the source article.
Key facts and history
Geophysics is one of the oldest sciences, with roots in ancient seismometers and magnetic compasses.[2] Earthquakes pose a risk to humans, and understanding their mechanisms improves risk estimates and engineering.[2] Every lunar day, which lasts 24 hours and 50 minutes, the Sun and Moon's gravitational attraction produces two high tides and two low tides.[2] Seismographs are the instruments that measure ground motions produced by these waves.[3]
Roughly 80% of Earth's internal heat comes from radioactive decay, which fuels both the geodynamo and plate tectonic movements.[4] The solar wind is kept at bay by Earth's magnetic field, which has its source in the fluid motions occurring within the outer core.[4] Plate tectonics is driven by the mantle, which behaves as a fluid over extended time periods due to its flow.[2]
What the research sources say
Mountains and ocean trenches further distort the planet's shape, and changes can be periodic, slow, or episodic.[5] Geoscience Australia states that the radiometric method estimates concentrations of potassium, uranium, and thorium near the surface.[6] Almost all gamma-rays detected near Earth's surface result from natural radioactive decay of these elements.[6]
References
- Wikipedia, "Geophysics" (CC BY-SA 4.0), which cites: ; ; ; Gutenberg, B., 1929, Lehrbuch der Geophysik. Leipzig. Berlin (Gebruder Borntraeger).; Runcorn, S.K, (editor-in-chief), 1967, International dictionary of geophysics: Pergamon, Oxford, 2 volumes, 1,728 pp., 730 fig; Geophysics, 1970, Encyclopaedia Britannica, Vol.10, p. 202-202 (original not read by us) en.wikipedia.org
- Wikipedia, "Geophysics" (CC BY-SA 4.0) en.wikipedia.org
- Wikipedia, "Geophysics" (CC BY-SA 4.0), which cites: Shearer, "Introduction to seismology", Cambridge University Press, 2009; (we also read that source) en.wikipedia.org
- Wikipedia, "Geophysics" (CC BY-SA 4.0), which cites: ; (original not read by us) en.wikipedia.org
- "Is the Earth round?", oceanservice.noaa.gov. facts only, no text reused. oceanservice.noaa.gov
- "Radiometrics", Geoscience Australia, 15 May 2014. facts only, no text reused. ga.gov.au
Each numbered sentence above was checked against the source it cites before publication. Sentences citing Wikipedia adapt text from the English Wikipedia article Geophysics (contributors), used under CC BY-SA 4.0; this entry is available under the same licence. Other sources were used for facts only; no text or images are copied from them.
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Sources
Compiled from Wikipedia and the sources listed below. Text from Wikipedia is available under CC BY-SA 4.0; this entry is adapted from it.
- Wikipedia: Geophysics (CC BY-SA 4.0).
- Word definitions: the , each quoted from its Wikipedia article.
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