_Amplitude._--The best measure of the amplitude was obtained at the
cemetery at Cherrapunji, situated near the southern margin of the
epicentral area. Here were two oblong masonry tombs (Fig. 69),
standing close together with their longer axes pointing north and
south. Their inner sides were partially destroyed. "On the outer
sides, they are almost intact, but the tombs have been driven bodily
down into the ground, and on either side to east and west, there is a
depression with a vertical side parallel to the outer surface of the
tomb and a smooth flat bottom over which the base of the tomb has
slid.... The edge of the western depression has the grass growing
undisturbed up to the edge of it, and along the edge small fragments
of lime and plaster show that this was originally in contact with the
edge of the tomb, which has now moved away to a distance of 18 inches.
On the east the edge of the depression is raised and the grass and
earth forced upwards by the thrust of the tomb against it; the breadth
of this depression is 10 inches."
During the movement of the ground, the tombs, owing to their inertia,
remained comparatively stationary, and the depressions were formed by
the backward and forward movement of the ground against them. The
movement on the east side was clearly arrested in some manner, and the
range therefore cannot have been less than 10 inches. It may have been
as much as 18 inches, and was probably, in Mr. Oldham's opinion, the
mean of these two amounts--namely, 14 inches. This would give an
amplitude of about 7 inches, a value which may be in excess of the
average amount elsewhere in the district, as the cemetery is situated
near the edge of a high sandstone scarp.
At Tura, also within the epicentral area, a range of not less than 10
inches was given by the sliding of a wooden house over the posts on
which it rested. Six months after the shock, Mr. Oldham frequently
noticed vacant spaces four or five inches across by the side of large
boulders scattered over the Khasi hills, and he infers that
"throughout the whole tract lying west of Shillong and Gauhati, as far
as the hills extend, and probably over a large area of the plains
besides, the amplitude of the wave-motion was nowhere less than 3
inches, while in many places it was over 6 inches."
Public-domain text, read in full here on John Shaqi.
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