Geoscience Reference
In-Depth Information
plitudes and long periods after traveling great distances. “hence,” quipped
John Milne, “the largest earthquakes have been called small.”
30
Milne him-
self preferred the term “unfelt earthquake” to microseism. the distinction
between micro- and macroseisms—one that has shaped the discipline's de-
velopment ever since—was thus a clumsy attempt to naturalize the growing
fissure between field-based and observatory-based methods.
in 1903 Montessus appeared at the second meeting of the iSA with a
warning: “the study of seismological waves originating at a distance has
the attendant drawback, that the earthquake phenomena lose their char-
acteristic features on the long path through the earth. it is to be feared that
their nature is veiled to us; the geological causes, the discovery of which is
the ultimate goal of our work, are in danger of escaping us.”
31
he made the
point more baldly the following year, noting that “by an unfortunate conse-
quence of this brilliant research, above all physical and mechanical, we have
increasingly neglected the geological point of view, the only one by which
it is possible to attack head-on the origins of the seismic phenomenon, and
we have delayed studying in itself a movement that, as interesting as it may
be, is not any less a merely secondary effect of earthquakes, such that these
studies remain incapable of reaching them [earthquakes] in their genesis.
Nonetheless a few brief considerations of the geology of the shaken regions,
including the descriptions of the most important seisms, would have suf-
ficed to remind the physicist-seismologists that they were directing their ef-
forts at a truly ancillary problem, despite the interest—entirely indisputable,
for that matter—of the results that they obtained.” to attack the earthquake
problem at its core, Montessus continued, seismologists had to get to the
scene of the action. those who sat tight in their observatories were like
meteorologists who hoped to understand the trajectories of cyclones based
only the “mechanical laws of the movement of fluids,” “without attending
to the atmospheric phenomena preceding and accompanying their forma-
tion at the very heart of the country where they are born.”
32
Seismology
could not be confined to the observatory, for its evidence was written in part
on the face of the earth.
Montessus's point concerned not only the methods of seismology but
also the identity of the seismologist. he should be “geographer and geolo-
gist” in addition to “physicist and engineer [
mécanicien
].” Most importantly,
the seismologist must remember his primary responsibility: “Science must
not only shut itself up in the ivory tower of its observations and specula-
tions. Whenever it can, and it is certainly the case here, it must think of
the well-being of humanity and of the relief of its sufferings.” to Montes-
sus, the purpose of the iSA was “not to predict earthquakes, but simply to
