Geoscience Reference
In-Depth Information
hardly be a coincidence.
31
First thing the next morning, Suess was on the
road, stopping to make inquiries in villages across Lower Austria. “Along
the entire line of this journey I received reports of the phenomenon.”
32
Further reports arrived in response to a request he printed in the major
Viennese papers, amounting to observations from a total of 203 localities.
Suess also drew on meticulous firsthand observation of the geology of the
region, gleaned from months of hiking and sketching (see figure 1.1), and
he combed provincial archives for accounts of past quakes. Suess soon came
to be seen as among the founders of a new school of seismological research,
based on what was termed the “monographic method”: “this investigates
an earthquake in and for itself and is concerned to study its unique aspect
and thence to draw conclusions about the various factors involved in this
quake.”
33
This style of research blended expert and popular knowledge: as
the author of a study of the 1858 earthquake in Žilina (Slovakia; German:
Sillein) had argued, in the study of earthquakes it was “very difficult . . . to
specify the limit where someone starts or stops being an expert.”
34
Suess's contemporaries studied earthquakes as symptoms of volcanic
forces, mine explosions, meteor strikes, the sinking deltas of lakes, or the
collapse of subterranean hollow strata; they also probed the possibility
of atmospheric or astronomical influences. For Suess, the significance of
earthquakes was altogether different: he sought “the relationship between
the structure of the earth's crust in a specific region and the direction and
nature of the shocks.”
35
The earthquake of 1873 would become an early
and particularly convincing piece of evidence for Suess's epochal theory of
global “tectonics”—the study of horizontal stresses in the earth's crust and
the mountains and basins they produce.
As Suess saw it, the major stumbling block of nineteenth-century geol-
ogy was the question of mountain formation. Charles Lyell believed he had
rid geology once and for all of the biblical deluge and with it anything that
smelled of “catastrophism.” The new orthodoxy was that the earth's surface
had been shaped over a previously inconceivable length of time by the slow,
steady processes of sedimentation and erosion. The gradual rise and fall of
the continents produced climatic changes, which in turn explained the ap-
pearance and disappearance of new species in the layers of the geological
record. This vision formed the backdrop to Darwin's theory of evolution,
and to most leading geologists it seemed impregnable. Yet Suess saw a con-
tradiction. Geologists were equally convinced that the earth as a whole was
contracting, as it cooled from an early molten state. on this view, moun-
tains formed as the planet's crust wrinkled like the skin of desiccating apple.
