Bubnoff unit

{{short description|Unit of rate of erosion in geology}}

The Bubnoff unit (abbreviated B) is a unit of speed defined as 1 micron (micrometer) per year. In other words, 1 B is equal to 1 meter in 1,000,000 years or 1 millimeter in 1 millennium.{{Cite book |url=https://archive.org/details/encyclopediaofwe0001alla |url-access=registration |title=Encyclopedia of weather and climate|last=Allaby |first=Michael |year=2007 |isbn=9780816063505 |location=New York, NY |publisher=Facts on File |pages=501 |oclc=69792154 }} It was defined in 1969.{{cite journal |doi=10.1130/0016-7606(1969)80[549:GTRTBU]2.0.CO;2 |issn=0016-7606 |date=1969 |volume=80 |page=549 |title=Geological Time-Distance Rates: The Bubnoff Unit |last1=Fischer |first1=Alfred G. |journal=Geological Society of America Bulletin |issue=3 }}

The Bubnoff unit is employed in geology to measure rates of lowering of earth surfaces due to erosion{{Cite book|title=A Dictionary of Geology and Earth Sciences|last=Allaby|first=Michael|publisher=Oxford University Press|year=2013|isbn=9780199653065|edition=4.|pages=82|oclc=835969159}} and is named after the Russian (German-Baltic) geologist Serge von Bubnoff (1888–1957).{{Cite book|title=A Dictionary of Environment and Conservation|last1=Allaby|first1=Michael|last2=Park|first2=Chris|publisher=Oxford University Press|year=2013|isbn=9780199641666|edition=2.|pages=60|oclc=810946330}} An erosion speed of 1 B also means that 1 m³ of earth is being removed from an area of 1 km² in 1 year.Kearey, P. (2001) The New Penguin Dictionary of Geology. Penguin, London, 336 pp. Compared to everyday phenomena, erosion is under most circumstances (excluding rapid events like landslides) an extremely slow process, calling for such a specialized unit. For instance, the current average rate of erosion over the Earth's landmasses has been estimated at 30 B (30 m in a million years). There are, however, great regional differences in erosion speed. As an extreme example, the watershed area of the Semani River in Albania is eroding at a rate of almost 3000 B (3 millimeters per year), the river having been estimated to transport about 4600 tons of earth per year from the average square kilometer in its watershed.Hall, A. (1993) The Work of Rivers. In Duff, D. (ed.) Holmes' Principles of Physical Geology, Chapman & Hall, London, 312-345.

The Bubnoff unit was introduced because of a desire for a standard unit to replace the multitude of units in use, such as feet per year, centimeters per year, meters per decade, and so on. One criticism leveled was that by introducing the Bubnoff unit, it would obscure the rate of erosion behind a unit no one besides specialists understood.{{cite journal |url=http://gsabulletin.gsapubs.org/content/82/12/3475.full.pdf |doi=10.1130/0016-7606(1971)82[3475:BUAO]2.0.CO;2 |title=Bubnoff Unit: An Objection |date=1971 |last1=Berg |first1=Robert R. |last2=Gangi |first2=Anthony F. |journal=Geological Society of America Bulletin |volume=82 |issue=12 |page=3475-3476 }}

1 m/s is equal to approximately {{convert|1|m/s|e12µm/year|3|abbr=unit|disp=number}} B.{{cite web |url=https://www.wolframalpha.com/input/?i=1+m%2Fs+to+bubnoff |website=Convert 1 m/s (meter per second) to Bubnoff units |publisher=Wolfram Alpha |access-date=1 June 2021 |title=Convert 1 m/s (meter per second) to Bubnoff units}}