Hi Petra. I don’t think the pumping out of the oil was the cause of fracture at the Baldwin Hill Reservoir although I’m sure it helped.

It appears that the injection pressures exceeded hydro fracture pressures and this is what caused the fault to move. The recorded timing of the fault offset (which was dutifully recorded by the reservoir owner) indicates the injection as being the decisive factor.

This was seen as you pointed out before with the injection of toxics into a well, or wells in Colorado.

It could have also be a combination of the weight of the water on the fault plus the pumping of the oil and the injection of water, which ultimately led to the slippage of the fault, which caused the reservoir to collapse.

The remains of the Baldwin Hills Reservoir stand empty today, the northern rim of the bowl like structure having been gashed from the crest to the foundation by the escaping water. A linear crack starting from the base of this gap can be traced across the asphalt floor of the reservoir. It reappears as a slight buckling of road pavement on the far side of the reservoir basin and then becomes a faint, discontinuous break in the ground surface, which trails off south of the reservoir into the brush-covered and excavation-scarred terrain of the Inglewood oil field.

There doesn’t appear to have been any one single quake that caused the collapse, or a quake that could have drawn someone’s attention to reservoir. There does however appear to be a sharp increase in quake activity within a 25 mile radius of the Baldwin Hills area. Starting on08/09/1963 and ending on 11/28/1963 there were 22 quakes with the largest at 3.4Ml on 09/14/1963. The next largest one was a 3.3Ml on 09/22/1963. Neither of these quakes appears to have occurred at the reservoir although I can’t say for certain that they didn’t. It appears to have been a gradual process until that final straw that broke the camels back. Take Care…Don in creepy town