Geoscience Reference
In-Depth Information
It follows from the biography of Petermann that the creation of geophysical maps
was an inherent part of his work. As his many maps document for inner Africa,
northern parts of the Russian Empire, and the Arctic regions, he showed an extraor-
dinary ability to transform data, usually provided by travel accounts, into carto-
graphic form. Along with his military maps, as for example his excellent map of the
battle near Hradec Kralove, North Bohemia in 1866, he mainly produced geograph-
ical and geophysical maps, among them maps of volcanic and seismic activities.
These areas of interest resulted from his cartographic education in the Cartography
Art School in Potsdam, founded and directed by Heinrich Berghaus (1797-1884),
author of the famous Physical Atlas published by J. Perthes in Gotha between 1837
and 1848 (Kozak and Vanek 2002). After 1840, Petermann continued this endeavor
in London. After his return to Germany in 1854, he became engaged in drawing both
geographical and physical maps for the publishing house of J. Perthes in Gotha. It
seems that Petermann was not specialized in seismological research of individual
earthquakes. On the other hand, the field was familiar to him due to his long-term
engagement in constructing numerous world and regional physical maps, in which
the effects of earthquakes were shown.
Volger, on the other hand, had most probably no special cartographic education
at all. From the preface of the third volume of his monograph (Volger 1858) it can
be concluded that he contacted the editorial house of Perthes in Gotha or its chief
cartographer Petermann, feeling the need to interpret the results of his earthquake
studies as a geophysical map. When studying the Visp earthquake, Volger invented
and utilized a seismic intensity scale for his own purposes. He subdivided the effects
into seven categories, designating degree zero for the epicenter region, and degree
6 for the lowest intensity site (Fig. 5). Since Volger designed the scale exclusively
for this one particular event of July 25, 1855 it was not suitable for classifying other
earthquakes, unless one would have accepted higher degrees of Volger's scale for
the classification of weaker events or degrees of negative values of Volger's scale
for the description of stronger events.
The first Petermann map was published in 1856 by Volger as part of a paper
that gives a short overview of the event and lays the foundation for his extensive
studies in the future (Volger 1856; as for the next paragraph see also Kozak and
Va n ek 2006). Petermann's data comes from a collection that Volger started right
after the earthquake (Volger 1855).
2
In this map, the intensity of earthquake effects
is classified in five degrees, according to five defined levels of seismic damage:
2
“Durch einen bereits am 27. Juli erlassenen und in alle Blatter der Schweiz verbreiteten Aufruf
habe ich m oglichst viele Leute der gebildeten Stande zu veranlassen gesucht, ihre Beobachtun-
gen sogleich niederzuschreiben und mir einzusenden. Diese Bem uhung hat, besonders in der
Deutschen Schweiz, ziemlich reichlichen Erfolg gehabt, die Zusendungen gehen noch immer fort,
es giebt ein betrachtliches Material zu verarbeiten. [On July 27, I caused an investigation to be
made by as many sophisticated people as possible. I enquired them to give notice of their obser-
vations, and send these to me. This endeavor was quite successful, particularly in the German part
of Switzerland, the returns still incoming; I received considerable material to process.]” (Volger,
1855).
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