Microseismicity related to potash mining
Date
1985
Authors
Journal Title
Journal ISSN
Volume Title
Publisher
ORCID
Type
Degree Level
Masters
Abstract
A seismic monitoring array was operated over the Potash
Corporation of Saskatchewan Mining, Cory Division potash
mine just west of Saskatoon, Canada in the thirty-nine
month period October, 1981 through December, 1984. The
array was set up to investigate macro- and micro-earthquakes
that occur regularly near the mine. 83 micro-earthquakes
and one macro-earthquake were recorded during the monitoring
period. In order to compute accurate locations for the
events recorded a suitable earthquake location algorithm had
to be found; standard linear location strategies could not
be used, because severe refraction of the energy travelling
from hypocenter to receiver rendered the problem non-linear.
A method of iterative approximation was therefore developed,
by which P-wave arrival times observed at the seismometer
stations are compared to calculated arrival times. The
method makes use of the Simplex Algorithm to home in on the
point in space which gives a "best-fit" (between calculated
and observed times) with a minimum of computation. Locations
were determined for 72 of the 83 micro-earthquakes
recorded. Events were mostly located near regions of active
or recent mining, with a few events located near regions of
local geological disturbances. Estimates of local event
magnitude were made for the 72 located events. Study of
the frequency of occurrence of the events, and of magnitude
relationships, imply that Cory micro- and macro-earthquakes
are fundamentally different. The relationship between micro
and macro events is not yet clear.
Description
Keywords
Citation
Degree
Master of Arts (M.A.)
Department
Geological Sciences
Program
Geological Sciences