[meteorite-list] WG: What is "meteorite awareness" and how does it influence fall statistics?

From: Jörn Koblitz <koblitz_at_meteoritecentral.com>
Date: Fri Jun 18 09:34:42 2004
Message-ID: <E5E6112EA31FA24CB448E091C6883C0517A26D_at_server2000.microfab.de>

Dear Mark,

I still think that this awareness (beside market pull and the increase in commercialization) is one important reason for the considerable increase of meteorite recoveries mainly as a result of systematic field search in hot desert areas.

It started with the systematic meteorite recovery and public relation program conducted by Harvey Nininger back in the 1930s (the average annual count of reported finds jumped from about 5 to about 20 meteorites). When Nininger went off "business" this rate fell back to values around 10 during the 1940s and 1950s and again rised to about 20 in the 1960s when lots of stone were found in the Roosevelt area. Unusual low numbers were reported in the 1990s. The number sharply jumped up in the last 6 year when meteorite were recovered on dry lakes in California and Arizona.

The case with the other hot desert areas (Sahara and Arabian Peninsula) is much more dramatic: first systematic field searches were conducted back in 1986 by geologists prospecting for oil fields in Libya (they did organized searched during their free time!) These searches yielded about 60 meteorites (named "Daraj" and are actually from "Hammadah al Hamra" area). Between 1989 and 1993 expeditions to Algeria (mainly Acfer and Tanezrouft areas) were organized and yielded 422 meteorites, for the first time including rare and scientific valuable material (e.g. the El Djouf / Acfer shower producing CR2). Due to the tense political situation and civil war in Algeria, focus of the meteorite hunters changed to Libya where more than 1200 meteorites were recovered between 1995 and 2001. In the late 1990s, DaG and HaH fields were already well grazed and it became more and more difficult to find further meteorites in reasonable time. The solution to this problem was Oman, an ideal recovery area. It yielded more than 100
0 meteorites to the present date. The problem with the limited time available for systematic field search by professional meteorite hunters was solved with money poured into Morocco as local people started to conduct systematic search, not only in their own country, but also in Western Sahara and Algeria. All these thousands of meteorites finds are know labelled "Northwest Africa".

A bit different is the situation with Antarctica. First systematic expeditions were conducted by a joined US/Japanese field team in 1974 after first meteorites were recovered in the Yamato Mounains back in 1969. Yamato and later the other blue ice fields around the Transantarctic Mountains (e.g. Allan Hills) yielded thousands of meteorites. This all took place long before systematic field search by private hunters began in the hot desert areas (Australia may be an exception here). Even though these Antarctic expeditions were organized by public institutions, "meteorite awareness" and the soaring interest in meteoritics and demand for scientific interesting material was the driving force for the US/ANSMET and Japanese/JARE programs.

Below is a more refined statistics of finds separated by country or find region.

J?rn
_______________________________________________________________________________
Joern Koblitz
MetBase Editor
The MetBase Library of Meteoritics and Planetary Sciences
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email: info_at_metbase.de
_______________________________________________________________________________


REFINED STATISTICS
TOT= total count (falls + finds)
OF: observed falls only
USA: finds from USA
ANT: finds from Antarctica
SAH: finds from Sahara (North African Counties incl. "Sahara" and "Northwest Africa" meteorites)
OMAN: finds from Oman
REST: all other countries

Year TOT OF USA ANT SAH OMAN REST
1900 17 8 4 0 0 0 5
1901 10 5 4 0 0 0 1
1902 12 7 1 0 0 0 4
1903 21 7 6 0 0 0 8
1904 11 4 0 0 0 0 7
1905 14 5 2 0 0 0 7
1906 13 7 4 0 0 0 2
1907 16 4 6 0 0 0 6
1908 14 7 5 0 0 0 2
1909 11 2 2 0 0 0 7
1910 20 11 1 0 0 0 8
1911 12 5 2 0 0 0 5
1912 12 5 3 1 0 0 3
1913 11 3 4 0 0 0 4
1914 18 7 3 0 0 0 8
1915 11 2 4 0 0 0 5
1916 20 10 3 0 0 0 7
1917 18 9 6 0 0 0 3
1918 15 6 5 0 0 0 4
1919 14 7 4 0 0 0 3
1920 15 5 3 0 0 0 7
1921 17 8 3 0 0 0 6
1922 15 6 5 0 0 0 4
1923 16 6 7 0 0 0 3
1924 18 10 4 0 0 0 4
1925 18 9 2 0 0 0 7
1926 13 7 4 0 0 0 2
1927 17 6 8 0 0 0 3
1928 16 6 6 0 0 0 4
1929 15 7 4 0 0 0 4
1930 20 11 6 0 0 0 3
1931 23 6 5 0 0 0 12
1932 26 8 7 0 0 0 11
1933 30 18 12 0 0 0 0
1934 27 10 15 0 0 0 2
1935 20 6 12 0 0 0 2
1936 34 5 25 0 0 0 4
1937 53 7 35 0 0 0 11
1938 44 11 25 0 0 0 8
1939 33 10 16 0 0 0 7
1940 38 5 31 0 0 0 2
1941 22 4 13 0 0 0 5
1942 20 8 9 0 0 0 3
1943 10 3 4 0 0 0 3
1944 19 7 6 0 0 0 6
1945 9 3 1 0 0 1 4
1946 13 6 2 0 0 0 5
1947 16 5 9 0 0 1 1
1948 22 3 12 0 0 0 7
1949 23 13 5 0 0 0 5
1950 38 12 18 0 0 0 8
1951 19 7 8 0 0 0 4
1952 17 6 5 0 1 1 4
1953 9 3 5 0 0 0 1
1954 20 6 10 0 0 2 2
1955 25 4 12 0 1 0 8
1956 24 8 8 0 0 0 8
1957 18 6 7 0 0 1 4
1958 19 2 4 0 0 4 9
1959 16 6 4 0 0 0 6
1960 30 6 5 0 0 0 19
1961 29 7 14 1 0 0 7
1962 35 8 15 0 0 0 12
1963 32 6 21 0 0 0 5
1964 31 8 12 0 0 0 11
1965 46 4 23 0 0 0 19
1966 27 6 11 0 0 0 10
1967 37 9 13 0 2 0 13
1968 52 4 31 0 1 0 16
1969 70 6 28 9 3 0 24
1970 46 8 19 0 1 0 18
1971 49 7 25 0 0 0 17
1972 31 3 18 0 1 0 9
1973 30 4 5 12 0 0 9
1974 689 7 8 663 0 0 11
1975 315 4 14 287 0 0 10
1976 62 12 17 22 0 0 11
1977 308 9 9 266 0 0 24
1978 384 3 18 353 0 0 10
1979 3.772 2 17 3745 1 0 7
1980 169 6 12 137 0 0 14
1981 489 7 25 447 0 0 10
1982 228 3 8 203 0 0 14
1983 478 5 20 439 1 0 13
1984 388 9 9 359 0 0 11
1985 374 3 10 355 1 0 5
1986 1.448 10 7 1389 17 0 25
1987 1.068 1 2 1022 34 0 9
1988 3.158 6 6 3132 8 0 6
1989 136 5 8 0 103 0 20
1990 1.575 8 7 1359 180 0 21
1991 842 6 5 600 141 0 90
1992 366 3 8 257 51 0 47
1993 957 4 3 888 14 0 48
1994 713 6 7 612 43 0 45
1995 486 6 5 283 183 0 9
1996 560 4 2 387 165 0 2
1997 1.684 3 5 1147 509 0 20
1998 492 10 13 194 265 0 10
1999 1.615 7 25 1075 360 138 10
2000 1.329 5 25 501 446 342 10
2001 939 3 29 203 209 482 13



> -----Urspr?ngliche Nachricht-----
> Von: minador [mailto:minador_at_yahoo.com]
> Gesendet: Freitag, 18. Juni 2004 07:39
> An: J?rn Koblitz; Meteorite-list_at_meteoritecentral.com
> Betreff: What is "meteorite awareness" and how does it influence fall
> statistics?
>
>
> Hi List,
>
> What is meant by "meteorite awareness"? I was using it to
> mean that people
> are familiar with the look, feel, etc. of meteorites. Until I started
> collecting and handling meteorites, I had a hard time
> distinguishing them
> from just looking at photos. And I had a hard time with
> meteorwrongs. Now
> that I'm more "meteorite aware", I'm pretty confident in identifying
> chondrites (at least fairly un-weathered ones - irons can
> still be pretty
> problematic for me).
>
> That being said, I suppose that increased "meteorite
> awareness" might not
> have much of an effect on falls or finds. Regarding falls, I think if
> people witness a fall, they're highly likely to report it
> even if they don't
> know what meteorites look like (or understand the concept of
> a meteorite).
> Maybe there would be less false reports.
>
> Regarding finds, I think the effect of more "meteorite
> awareness" would be
> less meteorwrongs being sent to labs (over the years my dad
> and I sent a few
> to ASU). It wouldn't necessarily be more being found since
> people tend to
> err on the side of caution and send every strange thing the
> find to experts.
>
> Maybe the reason that increased population density doesn't
> translate into
> more fall observations could be that the increases in
> population tend to be
> confined to urban areas. In this instance more witnesses
> might not have
> much of an effect. A fall like Park Forest would have probably been
> discovered even if it was a smaller urban area. There are
> still huge areas
> that are relatively unpopulated even though there are much more people
> around today. In fact I believe that since the Great
> Depression, there is a
> lower population density in rural areas (in the U.S.).
> People tend to bunch
> up in urban areas, and there are less farmers, logger and
> ranchers out there
> observing subtle changes that would escape the transient
> hiker, explorers,
> etc. I could be quite wrong on this though, so I'd like to
> hear more. I'm
> not denying increased urbanization, but considering that the
> Western U.S is
> ~80% public lands, the private areas being developed do not
> translate to
> much more "populated land area".
>
> I don't want to get too far from Tracy's question though.
> They got a bet on
> the line!
>
> Have a great night everyone (or day to those in merry old Europe and
> beyond!)
>
> Mark Bowling
>
> J?rn wrote:
>
> ----- Original Message -----
> From: "J?rn Koblitz" <koblitz_at_microfab.de>
> To: <Meteorite-list_at_meteoritecentral.com>; <markf@ssl.gb.com>
> Sent: Thursday, June 17, 2004 1:59 AM
> Subject: WG: [meteorite-list] Meteorite Fall Rates
>
>
> > If 'increasing meteorite awareness' would result in a net
> > increase then
> > why isn't that reflected in the figures?
>
> I think, that "meteorite awareness" will not really influence the
> statistics. The billions of people, mainly those living in
> highly populated
> areas with "low meteorite awareness" like China or India do
> highly influence
> the fall statistics (contrary to the find (NOT observed
> falls) statistics
> which is highly influenced by meteorite awareness).
>
>
>
Received on Fri 18 Jun 2004 09:35:03 AM PDT