4th Annual Seismology Workshop
Fluid-Induced Seismicity
16 August 2011
Council for Geoscience, 280 Pretoria Street Silverton, Pretoria, South Africa
The workshop provides a forum to discuss all relevant topics related to fluid-induced seismicity. Fluidinduced seismicity resulting from man’s interaction with nature is currently observed. Pumping fluids at
pressure to enhance or create permeability, fluid-extraction, reservoir-induced seismicity and flooded of
mines may affect the seismotectonic environment, which can lead to an increase in the level of local
seismicity.
The water flooding mine voids in the Witwatersrand Central Basin creates a significant environmental
impact as large voids are interconnected and are located dangerously close to the urban centres in and
around Johannesburg. Recent investigations conducted by the CGS water ingress management group
recommended that the water levels in the Central Basin be kept below the relevant environmental
critical levels by pumping of the mine water. Multidisciplinary skills are fundamental to a study of floodinduced seismicity, namely expertise of mine water management, rock engineering, structural geology
and mine seismology. The South African mining industry and research centres undertake a variety of
research and consulting work focused on fluid induced seismicity in mines. The programmes include
the permanent and temporary installation of local and regional seismograph networks to monitor ground
motion and monitoring the water level in old and abandoned mines.
The ultimate goal is to control the fluid-induced seismicity. This can be attained by focusing on
achievable tasks in the short term. The development of an early warning system would be a major
contribution towards disaster risk reduction. The nature of seismic events triggered by mine flooding, as
well as the damage potential of surface ground motions associated with such events, needs to be
monitored and investigated. The critical research needs are: fault imaging, accurate fluid tracking,
estimating fluid rates, establishing the volume threshold which causes unacceptable induced seismicity
levels, models which simulate the observed induced seismicity and models that predict stress
deformation from material properties and water levels in the flooded mines. Much could also be learnt
from the existing body of knowledge with regards to fluid-induced seismicity in mines, especially where
a large amount of data is already available.
Interested individuals, companies and universities are invited to participate in the Workshop.
Participation in the Workshop is free but registration is required before 9 of August 2011.
Dr Artur Cichowicz Pr. Sci. Nat
Senior Specialist Scientist, Seismology
Tel: +27 (0)12-841-1457
Cell: +27 (0)73-165-6400
E-mail: artur@geoscience.org.za
Workshop Program
Venue: Auditorium, Council for Geoscience, 280 Pretoria Street, Silverton, Pretoria
Date: Tuesday, 16 August, 2011
07:45 Registration
08:15
Welcome by Dr Ramontja, CEO of Council for Geoscience
08:25
Workshop objectives – A. Cichowicz (CGS)
08:30 “DMR’s perspective on fluid induced seismicity”
DMR official
08:45 “Geology of Central Basin”
09:00 “Environmental aspects of the water ingress into mine’
H . Coetzee(CGS)
09:15 “The roles of mine induced seismicity and mine water ingress in the Witwatersrand basin”
B. Zhao (University of Fort Hare)
09:30 "Dissimilarities in Lithology and basin characteristics of Central and West Rand group of rocks".
K . Prasad (CGS)
09:45 “Mine-Flooding Induced Seismicity in the Central and East Rand Goldfield: Maximum Expected
Magnitude”
V. Midzi (CGS)
10:00 "Evolution of seismic activity in the Johannesburg CBD and its effect on hazard and risk"
A. Kijko (Benfield Natural Hazard Centre, University of Pretoria)
10:15 “The impact of mine water on the change of hydraulic stress in the Central Rand Goldfield”
L. Lin (CGS)
10:30 "Recent seismicity pattern in the Central Basin and implication of civil engineering design “
A. Cichowicz (CGS)
10:45 – 11:10 Coffee break
11:15 "Some data recorded during the flooding of abandoned workings in a deep, geologically complex,
environment."
K. Bosman (Open House Management Solutions Ltd)
11:30 “Assessment of the boundary pillar between Savuka and Blyvooruitsig Gold mines”
S . Murphy (Anglo Gold Ashanti)
11:45 “Flooding and seismicity; Anglo Gold Ashanti’s perspective
L. Scheepers(Anglo Gold Ashanti)
12:00 “Seismic response to flooding and subsequent dewatering of the sub vertical shaft at Ezulwini Gold
Mining Company (Westonaria gold mine)”
T. Ward (Seismo-Gen)
12:15
Discussion
12:30 -13:25 Finger Lunch
13:30 “Multidisciplinary monitoring of flooding induced seismicity in Japan and what we can do in South
Africa”
H. Ogasawara ( Ritsumeikan University, Japan).
13:45 "McGarr's quantitative analysis of the seismic risk posed by the flooding of deep gold mines"
R. Durrheim (CSIR Mining Technology, Wits University)
14:00 “Deterministic Seismic Hazard: Expected ground motions from hypothetical large underground seismic
events induced by rising ground water”
E. Lotter (Institute of Mine Seismology)
14:15 “The role of crustal stress and water in fault reactivation: a simple mechanical model.”
M. Handley (Hands on Mining)
14:30 “Physical principles of fault reactivation by rising fluids in mine voids”
D. Birch (CGS)
14:45 Discussion
15:00 Coffee
Directions: Follow on the N1 North. Go past the Atterbury Road off-ramp take the Lynnwood
Road offramp and then turn right into Lynnwood Road. There are two lanes which turn right.
Keep in the left of these two lanes in order to turn left again into Meiring Naudé Road, which
runs parallel with the N1. Follow the map as indicated in red below.
Accommodation:
BB Weavind Place tel: 012-8040434 or cell 083-253-3913 walking distance from CGS