New Britain herald., 1927-08-01
QUAKES LOCATED
BY j. 5. BUREAU
Washington Seismograph One Of
First to Find Trenl0rS

Washington, Aug. 1 P-Within
few hours after delicate seismo-
graph needles at a score OF stations
over the western hemisphere began
sbignalling an earthquake May 20.
the Coast and Geodetic survey an
4punced from Washington that the
shock was serious one, and locat-
ed its incidence somewhere in the
kansu region of China. Two long
months after that announcement,
the actual news began to trickle in
from that isolated section Of China,
reporting that 100000 lives had
been lost in the disaster.
1t has now become a matter of
every day routine for Commander n.
H. Heck, the surveys chief Of seis-
biological study, and his staff to
locate with precision the spot af-
fected by earthquakes, even when
the disturbance, as in this case, is
10000 miles away from their quiet
chart room, separated by oceans,
mountain ranges and continents
Only the occasional emergence to
public note of a disaster of great
size makes the performance at all
unusual for them for earth trem-
blers are occurring every day.
Fortunately, Commander Heck
observes most of the continual
quakes shaking the earths surface
occur in spots where the damage
they cause is of little human mo-
ment Day by day, the seismograp hs
register disturbances somewhere,
but when the charts and the calcu-
lations are finished, the spot of oc-
currence is demonstrated most often
to be in the deeper parts OF the
ocean, and most frequently in the
vacant stretch of ocean between
Siberia and Alaska.
1t is only when the earth's crust
twists somewhere on land that con-
formations sometimes so CHASTITY as
that in Kansu province, can follow
the predictions.
Complete organization now OF the
observatories and workers behind
the survey work, Commander Heck
points out, makes the results OF
scientifically allocating every earth
quake possible.
In the case of the Kansu quake.
so eeismogra on the American
continents and in the Pacific area at
Honolulu, Samoa and other scatter
ed points, registered the distance.
The code kilograms and cables all
went instantly to Washington. CIV
ing the exact time as shown on the
individual chronometers at each
point, and describing the character
of shocks transmitted. 1t is with this
data that the work begins.
An earthquake anywhere SENDS
out from its shock center, the OBJ
servers now know, three and some
times four series of differing waves,
and the job Of locating the point
disturbed is tackled by the known
character and speed of the waves.
The first wave, travelling In a curved
line through the center of the
globe, moves more slowly at about
l IL miles per second, and the
fourth, occurring in case of the vlo-
lent shock, comes to the instrument
by completely circling the earth.
Most of the earth tremors never
are announced" Commander Heck
declared. 1T wouldn't be worth
while, for the quake is shown to be
in one Of the ocean depths where it
can never be reported, Once In a
while a steamer traverses a spot
when the disturbance is going on at
the bottom, and gets a sudden drip
ping shock. that leads its officers to
believe they have struck something.
The tidal wave generated usually
dissipates itself without attracting
attention.