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In-Depth Information
movement, not vertical, and the construction of a regional network of these
instruments was not completed until 1927. even then, Wood and his Cali-
fornia colleagues were repeatedly troubled by failures of the timekeeping
mechanisms on these seismographs.
130
By 1924, it was clear to Wood that tracking nearby earthquakes could
not be done by instruments alone. He turned to the public with a new sense
of urgency. From this point, Wood's outreach campaign was not merely a
matter of raising awareness of seismic risk and attracting research money. It
was an effort to recruit and train observers. this was not mere propaganda,
but rather a two-way exchange.
131
Wood realized that the observing guide he had published in 1911 had
“failed to enlist the services of voluntary observers, probably in part because
it did not present a concrete list of items or questions to be checked or an-
swered.”
132
So, having consulted with colleagues in europe, and drawing
on his knowledge of historical accounts of California earthquakes, he for-
mulated a new questionnaire.
133
It was essentially a list of “a great many of
the observations which commonly have been made in connection with the
occurrence of earthquakes, great and small.” He even provided readers with
models of questionnaires completed by hand, which he described as “ficti-
tious,” but “
founded
on reports actually made by ordinary, untrained observ-
ers. they are made composite in order to bring out points not adequately
emphasized in any single bona fide report at hand.” noteworthy on these
reports were descriptions of the observer's state of mind. Sample replies
included: “Dressing, still somewhat sleepy”; “Did not notice—too much
confused and disturbed”; “Could not discriminate”; “Unknown.” A report
of a weak shock ended with the comment, “the observer was awakened
with the impression of having experienced an earthquake. Some moments
later, while still awake, two or three rather slow, undulatory movements
were felt distinctly. the motion was slight and the shock would not have
been felt if the observer had not been awake and attentive. If the observer
was awakened by an earlier shock, as is believed, it must have been some-
what stronger.”
134
In these examples, Wood was defining and modeling a
standard of scientific observation. What he asked of the public was not un-
realistic, but nor was it trivial. Beyond frank and thorough reporting, he
demanded that observers calibrate their own degree of certainty. Wood's
questionnaire thus codified his working knowledge of the psychology and
sociology of earthquake response in Southern California, even as it was de-
signed to elicit a more reflective response.
