The ticking time bomb beneath Quetta
The Awaran district in Balochistan is the worst affected area of the September 24, 2013 earthquake. Killing at least 359 people, the massive quake razed homes and destroyed the district's infrastructure; tremors also affected dozens of towns in six other districts of the province.
Days after the earthquake, owing to severe damages to communication means and militancy, the survivors are still awaiting relief and rehabilitation.
According to the United States Geological Survey (USGS), the quake measured 7.7 on the Richter scale, with the epicenter laying 96 kilometres north of Awaran at a depth of 20 kilometres – and was the result of the very active Chaman fault.
The jolts were felt across Pakistan, prompting people in many cities, like Karachi, Hyderabad, Quetta and Kashmir to evacuate homes and offices.
Both, the April 2013 earthquake in Mashkhel and the September 2013 earthquake in Awaran have raised concerns about the threat of a massive impending earthquake, specifically in the Quetta region.
The calm before the storm
Din Muhammad Kakar, Assistant Professor in Geology at the University of Balochistan warns that elevated stress in the faults near Quetta is a strong indicator of an imminent earthquake.
Like the shell of a cracked egg, the upper surface of the earth is splintered into pieces called tectonic plates. Our planet consists of nine major and 12 smaller plates that are in constant movement.
Faults are essentially the cracks on the surface or at the plate boundaries; and their movements define the occurrences of earthquakes.
The three primary plates that are active in Pakistan are called the Eurasian, Arabian and Indian plates; all three plates conjunct near Lasbella. The subduction of the Arabian plate beneath the Eurasian plate is called the Makran Subduction Zone (MSZ).
Usually, earthquakes occur where these geological plates meet. As the plates push against each other, pressure is gradually built over time and then instinctively released, translating into an earthquake. The longer the interval between two quakes in the same area, the larger the amount of built-up pressure.
Pakistan is also home to the longest and most active fault lines in South Asia, the Chaman Fault System (CFS). At least 900 kilometres long, this fault is responsible for the 1935 Quetta Earthquake, which ranks as one of the deadliest earthquakes to have ever hit South Asia. A stem of the CFS, called the Ornach Fault is what triggered the recent Awaran earthquake.
The Chaman Fault is currently moving at the rate of 8-10 millimeters a year, equivalent to the width of the nail of a pinky finger.
“No activity has been witnessed in the north of the Chaman area in the last 115 years, which is a sign of enormous stress accumulation,” Kakar said.
He states that Quetta has been calm for more than 75 years; however, there is tremendous pressure building beneath its surface.
Hard facts, Cruel realities
To asses the threats to Quetta, with the help of some local universalities and institutes abroad, Kakar’s university placed two dozens sensors at various active points across Balochistan.
The Global Positioning System (GPS) based sensors confirmed that the faults were undoubtedly gathering stress in Quetta, with velocities moving southward at the rate of 8-10 millimeters per year.
Additionally, Kakar has been urging the authorities for quite some time now, to use strict building codes and preparedness and response plans for the city.
“With Quetta being highly susceptible to earthquakes, it is appalling that we still do not have any emergency plans for the city. Almost 50 per cent of Quetta perished in the 1935 earthquake. There is no telling how much more damage the next earthquake may bring,” he added.
Islands of opportunity
A few hours after the earthquake struck Awaran, a small island arose near the waters of Gwadar. Within a span of two days, two more islands popped up along the coast of Ormara and Pasni.
Experts claim that these structures are mud volcanoes that suggest continuous methane emission, thus projecting great hydrocarbon potential.
Locals in the area expressed a feeling of déjà vu upon the emergence of these islands, having already witnessed the rise of a soft muddy island in November 16, 2010 off shore in Hingol.
Anwar Hussain, Deputy Director of Geological Survey of Pakistan, Karachi, visited the Hingol mud volcano for research purposes.
“The Hingol mud volcano was much larger than these three islands that have recently appeared. It has by now submerged back into the water, as the appearance and disappearance of these mud volcanoes is a fairly common phenomenon in the area,” Hussain explained.
“I discovered methane gas seeping from various spots in the Hingol volcano. Sulphur and some traces of copper were also detected,” he added.
Similar mud volcanoes have been found near Gwadar. One of the highest and biggest in the world, Chandragup (Moon Volcano) is also located in close proximity.
Anwar Hussain said that the offshore area of the Makran coast shows tremendous potential of methane gas. He recommended a comprehensive geophysical analysis to further explore this potential.
Similarly, experts from the National Institute of Oceanography (NIO) have also indicated awareness of frozen methane in the area.
The ticking bomb
Pakistan has suffered two devastating earthquakes in recent history, with the Quetta earthquake in May 1935 killing at least 30,000 people and the Pakistan-administered Kashmir earthquake in October 2005 killing 75,000 people.
While it was the Chaman Fault that triggered the Quetta earthquake, the Kashmir earthquake was a result of the collision between the Indian and Eurasian plates.
However, the gravest geological bomb that now ticks is the Makran Subduction Zone (MSZ). Located in the Arabian Sea, this is the precise point where all three tectonic plates are active with each other.
On 28 November 1945, Pasni and some parts of Ormara were overwhelmed by huge waves, measuring up to 12-15 meters in height, when the 8.1 magnitude earthquake hit the MSZ.
More than 4000 people died in the Makran earthquake, the giant waves brought to shore hundreds of thousands of dead fish and destroyed many villages in its wake.
Experts warn that the recurring frequency of earthquakes and tsunamis in the MSZ is 100-150 years.
An earthquake from the MSZ area was also reported in 326 BC. And seismic activity in the region was registered in the years 1008 and 1897.
A study based on the tsunami hazard in the MSZ by a team of Iranian experts concludes that the zone has a high probability of witnessing a huge tsunami within the next 50 years.
Additionally, the study suggests that the Makran and Gwadar coasts are also vulnerable to a tsunami attack, owing to the two islands that emerged there after the 1945 quake.
The Deputy Director of GSP Islamabad, Asif Nazeer Rana said that historically, Makran has been hit by tsunami in the past.
“The entire Makran Coast is vulnerable to a tsunami triggered by a 7.5 or above magnitude earthquake, this will result in serious repercussions for Karachi as well,’ he added.
Gemma L. Smith and her colleagues from the University of Southampton recently published a paper on the Makran Zone.
The team has developed a two-dimensional thermal model of the subduction zone, which suggests that earthquakes ranging from 8.7 to 9.2 magnitudes are probable, approximately within 350 kilometers of the area, with a reoccurrence frequency of 100-200 years.
Pakistani experts have also warned that the two earthquakes in 2013 that struck Balochistan could further trigger pressure towards the already pulsating Makran Zone.
With the ever-increasing evidence of such approaching harsh realities, it is time for Pakistan to take steps to ensure immediate emergency preparedness and response plans to save thousands of precious lives.