BOX – 5
GROUND FAILURES EARTHQUAKE OF 13 JANUARY 1993 Epicentre: Port Royal
Mts., Upper St. Andrew;
Magnitude: Md 5.4
Locations of failures:
1. Hope - Liguanea Fan
off the coastline of Seven Miles, Bull Bay:-Submarine Cable TCS-1 suffered a tension break due to submarine slumping 1.944 km from Seven Miles at a depth between 100-200m; about 0.3 km of cable damaged.
Jamaica/ Panama SD Cable suffered a tension break due to submarine slumping 1.98 km from Seven Miles; about 3 km of cable was buried under the debris.
2. Northern approach roadway to Portmore Causeway Bridge:-
Longitudinal cracks of varying dimension (max. Width 25 mm, length 36 m, visible depth 35 cm) in the fill due to liquefaction of subsoils.
3. Mona Reservoir:
A ground crack (3 cm wide and 15 m long ) in the centre of the embankment road on the southwestern side of the reservoir, due to liquefaction in fill material.
4. Rio Cobre Pipeline, Caymanas Estate:
Disruption of joints over a 1000 m length of pipeline laid in water logged sands due to liquefaction related ground settlement.
5.
Yallahs Pipeline:
Landslide debris-covered washouts and air valves at sections of the pipeline between Hope River to August Town, Rest Haven to Bull Bay, Cambridge Hill to Eleven Miles.
6. Newcastle to Buff Bay Road:
A major rock slide, 800 squares m, blocked the road between milepost 22-23.
7. Papine, Gordon Town to Mavis Bank Road:
Several landslides including lateral spreading near Coffee Factory which damaged a water pipeline.
8. Newcastle Road:
Several landslides, ground cracks
9.
Maryland - Woodford - Freetown Road:
Several landslides, ground cracks, ground settlement
10. Jacks Hill area:
Ground cracks
11. August Town area:
Ground cracks, ground settlement
12. Mona Heights:
Ground cracks
13. Rockfort Mineral Spring:
Excessive water flow at the spring. Besides the above, there are reports of ground cracks and ground settlement from a number of localities in Kingston and St. Andrew.