The most memorable geological event that I had directly experienced occurred when I was at the final year of my undergrad. It was a rockfall – a man-induced one.
My final year thesis was to investigate the geological strucutures in a Permian sedimentary unit in Hong Kong. The unit exposes only at the coastal section of a small isolated island which is connected to the mainland by a tomobolo. My project was to measure the orientations of the folded layers and determine the folding patterns, deformation phases etc.
On one particular field day, I invited my best friend and classmate, Brandon, to assist my field work. So, we walked along the coastal section, making records and measurements of the geological structures along the way. And then, we arrived at an outcrop which was essentially a cliff. Some sub vertically dipping rock layers were nicely seen, but we would need to make a 1-2m climb on the rock face to reach the point where we could make a good measurement. Brandon was a stubby young man then, had kindly offered to help me to do the measurement, when I could stay on the ground and record the strike and dip.
Somehow, we were young, inexperienced and probably too careless. We had not judged the conditions before acting. Brandon climbed up the rock face with one of his hands holding a geological compass. He probably did not realise that he was holding onto a rather loose boulder in one of his moves. All of a sudden, the boulder moved and toppled. It hit Brandon’s chest, and bonunced. Brandon fell with the boulder and I was just beneath them at the toe of the slope.
Although it was probably not a life threatening event, but it was quite scary. The boulder was blocky, about half a metre in diameter, and Brandon was over 150 or 160 pounds. They fell just next to me. It was certainly a near miss. Luckily, Brandon did not get serious hurt, but minor bruise.
What was the lesson learnt? Well, for me, never stay too close below a cliff when someone is climbing. And for Brandon, never trust a rock outcrop, it may not be able to support his own weight. OK, seriously, the lesson learnt was the importance of safety when doing fieldwork. Even a minor mistake, or a misjudgement, or carelessness, may result in serious consequence. Looking back after more than 13 years, I still believe that I was very lucky.