Submarine cables seem to be more impacted by earthquakes in the past five years or so than I can ever recall in the past. Whether that is because there are more earthquakes, whether their magnitude is greater or whether there are just more cables available to be affected, I really don’t know. But historically we rarely saw any effect. Maybe it is just the location of the quakes.
For all its magnitude, the 2005 Sumatra earthquake and tsunami had minimal impact on the network with one reported outage in Malaysia. The 2006 quake and submarine landslide in the Luzon Strait opened our eyes to the interruptions that can occur when we saw some eight breaks in 16 cables. No one was able to remember such a sizeable interruption. 2009 saw the Luzon Strait hit again with breaks in six cables resulting from Typhoon Morakot.
Now in 2011, we have the earthquake off Japan. Measuring 8.9, its epicentre was 72km off the coast. This was a big one. It triggered a massive tsunami which swept across the Honshu coastline in the Sendai region. It killed many thousands of people. Additionally after the waters had settled, at least six cables were broken and it appears that there are more than a dozen breaks in total as some cables scored more than one.
A severe consequence of the tsunami was the impact on the Fukushima nuclear power station complex and damage to several of the reactors. This caused leakage of radioactive material and consequently high levels of radiation. As the ships approached the repair zone, it became apparent that some faults were in the exclusion zone where radiation levels were well above the safety limit.
To make the repairs could have put the lives of the crew at risk. This seems to be the first time that radiation has been an issue in meeting a contractual obligation to do the repair. In addition to the danger to the crew, there was the risk that a cableship would become contaminated. Post-event de-contamination would be a difficult and expensive exercise. Insurance cover ceases if a ship enters the radiation zone. So much of the repair work ground to a halt waiting for the radiation levels to fall to a safe level.
It is now eight weeks since the earthquake and while work is proceeding on repairs outside the exclusion zone, repairs inside are on hold. A certain amount of confusion has occurred as radiation was not well covered in some of the maintenance contracts. I expect we will see amendments to future marine maintenance contracts to cover this.
