A rate of erosion leading to a loss of 1 millimeter in 1000 years (which is the same as 1 micron/year or 1 meter in 1 million years). .
The Bubnoff unit (B), defined as = 1 mm/thousand years = 1 m/million years, is proposed as standard measure for geologic movements and increments.¹ Symbol, B. It was named for Serge von Bubnoff (1888-1957) a rate of erosion or of the deposit of sediemnt.
In short order expansion proposed an expansion of the defintion, micro and Mega- bubnoff
Then resistence “Consistent use of a uniform system of fundamental units is vital to scientific communication, but the naming of such units is unnecessary and obfuscatory.”³ This is much the same current policy of the BIPM in regard to derived units.
By the 1980's the unit was found in standard texts:
The unit 1 mm per 1000 years, equivalent to 1 m per million years, has been named the Bubnoff unit, after Sergei von Bubnoff, a German geologist of Russian background working in the early twentieth century. This unit (abbreviated as B) is coming into increasing use as geologists focus on rates of erosion and comparable rates of sedimentation, crustal subsidence, and crustal uplift.⁴
1. Alfred G. Fischer.
Geological Time-Distance Rates: The Bubnoff Unit.
GSA Bulletin, vol 80 no 3, pp 549–552 (1 March 1969).
2. J. Mark Erickson.
Geological rate units.
Compass, vol 47, no 1, p. 5-9. 1969.
We provide this citation because it is said to have suggested greatly expanding the phenomena to which the unit might be applied. However, we have not been able to locate a copy of this article. The gist of it man be gleaned from the author's abstract, taken from page 1212 of U.S. Dept of Interior, Abstracts of North American Geology, August 1970:
Geologists are urged to adopt Fischer's recently (1969) proposed Bubnoff unit (B) as the standard geologic time-distance rate unit (B = one micron per year = 1 mm per 1,000 years) for all geological rates. In order to hasten acceptance of B in the geologic vocabulary, a table of values for conversion of English notation into B units is given herein. Future applications of B, such as construction of isobubnoff contour maps, should be recognized. Finally, since rate situations which employ very large distance components, or very short time components, are important, the Megabubnoff (MB)and microbubnoff (μB) units are here proposed to make notation more flexible under such circumstances. The Megabubnoff unit, MB, has a value of 1 × 10⁶ B, and the microbubnoff unit, μB, is 1 × 1000⁻³ B. It is urged that these rate units be employed in all discussion of geological rates for the betterment of scientific communication.
3. Robert R. Berg and Anthony F. Gangi.
Bubnoff Unit: An Objection.
GSA Bulletin, vol 82 no 12, pp 3475–3476 (1 December 1971).
4. Frank Press and Raymond Siever.
Earth. (4th edition)
New York: W.H. Freeman and Co., 1986.
Footnote, page 132.
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Last revised: 21 May 2023.