Eotvos (unit)
| eotvos | |
|---|---|
| Unit system | Non-SI metric unit |
| Unit of | Linear acceleration density |
| Symbol | E |
| Named after | Loránd Eötvös |
| Derivation | 10−9 Gal/cm |
| Conversions | |
| 1 E in ... | ... is equal to ... |
| CGS base units | 10−9 s−2 |
| SI base units | 10−9 s−2 |
The eotvos is a unit of acceleration divided by distance that was used in conjunction with the older centimetre–gram–second system of units (cgs). The eotvos is defined as 10−9 galileos per centimetre. The symbol of the eotvos unit is E.[1][2]
In SI units or in cgs units, 1 eotvos = 10−9 second−2.[3]
The gravitational gradient of the Earth, that is, the change in the gravitational acceleration vector from one point on the Earth's surface to another, is customarily measured in units of eotvos. The Earth's gravity gradient is dominated by the component due to Earth's near-spherical shape, which results in a vertical tensile gravity gradient of 3,080 E (an elevation increase of 1 m gives a decrease of gravity of about 0.3 mGal), and horizontal compressive gravity gradients of one half that, or 1,540 E. Earth's rotation perturbs this in a direction-dependent manner by about 5 E. Gravity gradient anomalies in mountainous areas can be as large as several hundred eotvos.
The eotvos unit is named for the physicist Loránd Eötvös, who made pioneering studies of the gradient of the Earth's gravitational field.[4]
References
- ↑ "Basic measurement units / GOCE / Earth Explorers / The Living Planet Programme / Observing the Earth / Our Activities / ESA". http://www.esa.int/Our_Activities/Observing_the_Earth/The_Living_Planet_Programme/Earth_Explorers/GOCE/Basic_measurement_units.
- ↑ Glossary of the mapping sciences. American Society of Civil Engineers., American Congress on Surveying and Mapping., American Society for Photogrammetry and Remote Sensing.. New York, NY: American Society of Civil Engineers. 1994. pp. 177. ISBN 0784400504. OCLC 30893371.
- ↑ "Gravity in detail - Content - Earth Online - ESA". https://earth.esa.int/web/guest/-/gravity-in-detail-5728.
- ↑ Adelberger, E. G.; Heckel, B. R.; Smith, G.; Su, Y.; Swanson, H. E. (1990). "Eötvös experiments, lunar ranging and the strong equivalence principle" (in en). Nature 347 (6290): 261–263. doi:10.1038/347261a0. ISSN 1476-4687. Bibcode: 1990Natur.347..261A.
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