SEGAMAT: The cracks that have appeared on a farm in Jalan Buloh Kasap, Batu 2, here have yet to be confirmed as being linked to the weak earthquakes recorded in the district between Aug 24 and 30.
Johor Mineral and Geoscience Department (JMG) director Noorazhar Ngatimin said tremors likely caused the cracks, but this could not be confirmed as the area consists of soft soil layers.
"The resistivity test was conducted to obtain subsurface data on rock profiles and layers quickly, as well as to detect the presence of cracks.
"The brief study carried out recently only involved 2D profiling, not 3D, and could only detect depths of 30 to 35 metres. Normally, earthquake studies are conducted up to a depth of 800 metres," he said when contacted by Bernama on Tuesday (Sept 2).
He said the initial inspection also detected traces of cracks below the surface, but there was no evidence of cracks occurring in the hard rock layer underground.
Noorazhar said the department had also not analysed the tremors or made any estimate regarding the possibility of follow-up incidents after a series of tremors last week.
"Apart from being possibly caused by tremors, the surface cracks could also be due to extremely hot and dry weather, but usually such cracks do not extend into the subsurface area," he said.
According to him, Johor has six seismometers that record tremor readings, located in Gelang Patah, Johor Bahru, Batu Pahat, Kluang, Kota Tinggi and Mersing.
He said weak tremors are difficult to detect because the instruments only register tremors of magnitude 4 and above, noting that even heavy vehicles passing on roads can trigger readings.
On Aug 31, Noorazhar and several JMG officers visited and inspected resident's home in Batu 2, Jalan Buloh Kasap, following the appearance of cracks after a weak earthquake last week. – Bernama
