Residents of countries located on the edge of the Pacific Ocean seem to be experiencing more natural disasters than usual, however one of Australia’s quake experts says the apparent cluster of events is no more than a coincidence.
As Mexico recovers from last Tuesday’s deadly 7.1 magnitude earthquake, Japan and Papua New Guinea also felt shocks last week in the 6.0 range.
Meanwhile Vanuatu and Bali have experienced widespread evacuations in the last few days due to volcanic activity, affecting thousands of people.
Despite some chatter that these events are an indication to prepare for the worst, Geoscience Australia’s senior seismologist Professor Phil Cummins says it would be hard to link each specific event.
“I think it’s just by chance that a lot of these things are happening at the same time,” Professor Cummins told SBS World News.
“It’s very difficult to explain how earthquakes and volcanoes that are [located] quite some distances from each other are coupled.
“The mechanism that causes an earthquake here and to cause a volcanic eruption a great distance away is very poorly understood.
“We can’t explain that and we just have to regard it as a random clustering.”
Professor Cummins said that the activity was related in so far as all the events were located in the Pacific Ring of Fire - the horseshoe shaped ring of volcanic and earthquake activity that lines the Pacific Ocean.
View of the Popocatepetl volcano emitting a column of steam and gas, from San Andres Calpan, Mexico Source: AAP, EFE
“All of these things are somewhat related, they’re all affected by the state of stress in the Earth’s interior... so in some sense they are related.”
However, he found it difficult to believe that each incident was directly related or caused by a previous one due to the great distances between each specific event.
“My personal feeling is that they are not causally related,” he said.
“When you get a large event that is soon followed by another large event in the immediate vicinity, then it is much easier to believe they are related.”
He used the 2004 Sumatra earthquake and tsunami, and subsequent Sumatra earthquakes as an example of this.
“But when you get Mexico, followed by Japan or Vanuatu, I tend to think it’s probably just a random clustering in time.”
However, Professor Cummins said it was possible for a large quake to cause strong seismic waves that could lead to further earthquakes occurring even at quite large distances from the initial one.
Rescue workers search a building in the Roma neighbourhood of Mexico City Source: AAP
He also noted earthquakes did typically have a pattern of foreshocks, a main shock and a series of aftershocks within the same area.
However, “This isn’t a pattern that happens all of the time,” he said.
When asked how concerned we should be about the amount of activity in the Ring of Fire in the last few weeks, Professor Cummins said there was not a lot we could do.
“For earthquakes we cannot really count on a warning... the early warnings given by the sophisticated systems in Japan and California are tens of seconds or a minute at most,” he said.
“There really is no silver bullet earthquake prediction method, but seismology and science can help societies to better prepare by estimating how strong the ground shaking caused by earthquakes is likely to be, so we can design buildings to withstand this.
“We have to be aware that quakes could happen at any time,” he said.
Some of the world’s biggest cataclysmic events have occurred in the Pacific Ring of Fire.
The Indian Ocean earthquake and tsunami in 2004, the Chile earthquake in 1960, and Japan and New Zealand quakes in 2011 are some of the more recent devastating effects of living inside the ring.
There have also been major volcanic eruptions in the Ring of Fire, including the 1883 eruption of Krakatau in Indonesia and the 1991 eruption of Mount Pinatubo in the Philippines.
While these large scale deadly phenomena are fortunately infrequent, the agricultural and tourism benefits of living in the area around a volcano explain why so many are happy to continue to do so.
“Volcanoes can be very attractive as they offer fertile soil, usually for a very long period between eruptions. It’s good for farming and the pressure to populate these areas can be pretty irresistible,” Professor Cummins said.
Ring of Fire's fury
Mexico's Popocatepetl volcano roars back to life spewing ash and smoke
