WHEN BIGGER ISN'T BETTER... (reprise)

Earthquakes and megacities: a recipe for catastrophe

Courtesy of National Geographic

WASHINGTON, Feb 28, 2010 – Megacities are something new on the planet. Earthquakes are something very old. The two are a lethal combination, as seen in the recent tragedy in Port-au-Prince, where more than 200,000 people perished — a catastrophe that scientists say is certain to be repeated somewhere, and probably soon, with death tolls that once again stagger the mind. In 1800, there was just one city with more than a million people — Beijing. Now there are 381 urban areas with at least a million inhabitants. Urbanisation crossed a threshold last year when, for the first time, more people lived in city settings than rural ones. About 403 million people live in cities that face significant seismic hazard, according to a recent study by seismologist Roger Bilham of the University of Colorado.

 

The next Big One could strike Tokyo, Istanbul, Tehran, Mexico City, New Delhi, Kathmandu or the two metropolises near California’s San Andreas Fault, Los Angeles and San Francisco. Or it could devastate Dhaka, Jakarta, Karachi, Manila, Cairo, Osaka, Lima or Bogota. The list goes on and on. “You can name about 25 cities that are like Port-au-Prince. They’re not going to shake much but every 250 years (on average they will). So if you can name 25 of them, you’re going to have an event like this every 10 years,” said David Wald, a seismologist with the US Geological Survey. In many vulnerable cities, people are effectively stacked on top of one another in buildings designed as if earthquakes don’t happen.

   

It is not the tremor that kills people in an earthquake but the buildings, routinely constructed on the cheap, using faulty designs and, in some cities, overseen by corrupt inspectors. 

The difference between life and death is often a matter of how much sand went into the cement or how much steel into a supporting column. Earthquakes might be viewed as acts of God, but their lethality is often a function of masonry. “In recent earthquakes, buildings have acted as weapons of mass destruction,” Bilham wrote in the journal Nature. For years, earthquake scientists have shouted their warnings about the strong likelihood that a major quake would level an impoverished city and kill hundreds of thousands of people. They have said, for example, that Nepal’s Kathmandu, where masonry structures expanded so haphazardly that some eventually cantilever over narrow city streets, was every bit as vulnerable as the surrounding Himalayas are majestic. They have said that a million people could die in a major quake in Tehran, Iran.

What’s impossible, however, is knowing precisely which of these cities will be the next to crumble. Or when. For all practical purposes, scientists can’t predict earthquakes. The theory of plate tectonics, largely developed since the 1960s, explains why earthquakes happen in general. 

The major plates of the earth’s crust move constantly, creeping along at about the speed of fingernail growth. They rarely move smoothly past one another but are usually locked in place. On a strike-slip fault of the type that ruptured in Haiti, strain builds on the fault line for decades or centuries. The fault in Haiti had not ruptured in 240 years. An earthquake is a sudden, stress-relieving event. The fault is said to “break.” Scientists can map faults and estimate how much strain has accumulated since the last quake. What they can’t do is say that a given fault will break tomorrow or next year or 10 years from now. Any calculation of earthquake probabilities has a lot of slop in the numbers. “The problem is, the slop is huge on a human time scale,” said Susan Hough, a seismologist with the US Geological Survey. “We’re wired to deal with the immediate. We’re not geared to plan and stress about things likely to happen in 30 years.”

Some large earthquakes have small precursors, called foreshocks, but others happen without warning. There is one famous case of earthquake prediction, in Haicheng, China, in 1975. A local official sounded the alarm after many foreshocks and reports of snakes emerging from hibernation. But that prediction was more akin to a hunch than a scientific argument. There have been countless, less publicized instances when predicted earthquakes did not materialize. As Hough notes in her book “Predicting the Unpredictable,” the successful prediction of earthquakes was an official government mandate in Mao Zedong’s China, but no one foresaw the killer quake that took at least 240,000 lives in Tangshan in 1976.

 

Port-au-Prince had not been hit with a major quake since the days of French rule in the 18th century. Only in recent years have scientists mapped the fault that runs near the city. “Just the beginning of work had been done. But enough was known that it could produce a big earthquake,” said Carol Prentice, a geologist with the US Geological Survey. “We knew it would be bad, but I didn’t imagine that it would be this bad.” 

[Source: The Washington Post. First posted 28 February 2010]

Is the Selangor Dam Running Dry? ~ still waiting for the answer!

Not since 2002, when Gamuda began filling the Selangor Dam, have I seen the water level as low as this. In the wake of the 26 December 2004 Sumatran undersea earthquake and tsunami that killed more than 300,000 - the water level in the dam sank to less than 40% of its capacity. Soil tests were conducted by Gamuda to determine where the water was leaking out. There were fears that huge volumes of fast-flowing subterranean water might eventually cause enormous sinkholes - huge enough to swallow entire towns.


The shifting of the tectonic plates off the Sumatra coast may have moved the dam wall slightly too, since it is located only a few hundred yards from a suspected seismic fault line. Rumors were rife that one of the gigantic turbines in the outlet pipe had been crushed and navy frogmen were engaged to inspect it. Mysteriously, the "leaks" appeared to have repaired themselves and soon the dam lake began filling rapidly again.

There have been no recent earthquakes in the vicinity, not even a tremor... so how come the water level has gone steadily down over the last four or five months? I estimate that the lake is now at least 35 feet lower than capacity.

A muddy column of water thrusts itself into the lake, 
taking on the ominous appearance of a naga (dragon).

Has the federal government been pumping out half the lake to fill police water cannons in anticipation of more street protests? Is Syabas draining the lake so they can sell the Pakatan Rakyat state government an empty reservoir full of silt? Or have more fissures suddenly appeared at the bottom of the lake? After all, the entire area is full of hot springs, the granite bedrock is heavily fragmented, and was indeed classified by geological survey teams in the 1950s and 1970s as a "high erosion risk" zone.

The annual "haze" generated by oil palm cultivators (local as well as Indonesian) 
hangs over the lake like a suffocating mist.

Photography by Antares

THE ORANG ASLI say we cannot destroy them without ourselves being destroyed. To illustrate this, they recount a hoary legend that warns of divine retribution against those who would drive them from their birthplace, their beloved pusat negeri - for they were indeed born in the navel of the nation, in the verdant foothills of Gunung Raja - only a few miles, as the eagle flies, from the site of the proposed Selangor Dam.

And how would "divine retribution" destroy those who seek to displace them from their rightful home? Invariably, the totem naga is invoked. The dragon, guardian of the rivers, would roar in primordial rage and return to the ocean depths, its thrashing tail wreaking havoc all the way. The very earth will quake and fill with swirling floodwaters, tall buildings will shake and crumble into the mud. A deliciously apocalyptic vision, no doubt, but can it be translated into scientific terms?

Quite easily in fact. If you allow that the dragon is how "primitive" folk describe electromagnetic phenomena generated by disturbances in the earth's magnetic field, then the Orang Asli doomsday scenario translates as RIS. That's technical jargon for Reservoir Induced Seismicity - where the sheer weight of a large body of water exerts enough pressure on the tectonic shield or plate boundaries to trigger earth tremors where none have been known to occur.

Not very much is known about these quirky quakes, except that only too often they have been completely ignored or overlooked by overconfident builders of large dams. (Any structure over 15 meters is considered "large" which qualifies the proposed Selangor Dam as "titanic" at 115 meters.)

And, of course, water is a persistent and persuasive agent that works its way over, under, around and through "solid" bedrock in utterly mysterious ways. The notion of solidity or stability, we now know, is purely that - no more than a notion. If a 250-year-old bank can spontaneously collapse as a result of an earthquake 11,000 miles away, what more a 500-million-year-old embankment? Especially when you have irate dragons on the loose...

Antares
6 March 1999

Selangor Dam Lake idyll by Jhueilee

WATER WOES: SELANGOR DAM PROVES TO BE NO SOLUTION
By Sam Hui & Antares
Letters to Malaysiakini | September 23, 2005 | 1:58pm

Seven years ago, the government insisted that the construction of the Selangor Dam was "unavoidable" because of the El-Niño effect. Save Our Sungai (SOS) Selangor and other concerned NGOs advised against it and pointed out that the root causes of the 1998 "water crisis" were:

* inefficient water distribution;
* careless per capita water usage;
* wasteful leakage in the antiquated pipe system; and
* reckless denudation of watershed areas, in turn affecting rainfall patterns.

Concerned civil society groups have emphasized for years that stringent forest and water conservation, replacing leaking pipes, and appreciating the true value of water are how we can ensure sustainability of our water supply.

Obviously, the government did not heed this sound advice and went ahead with the dam construction. The outcome?

A whitewater rafting haven has been sacrificed; one of the world's largest fire-fly colonies is threatened with extinction; an entire Orang Asli village has been relocated to a virtually inaccessible hill; and 600 hectares of lush river valley, once teeming with rare species of flora and fauna, have been inundated.

It now appears that SOS Selangor's warning about the dangers of building a dam near a suspected seismic fault line is being borne out. Since the massive Sumatran earthquake of Dec 26 which spawned the killer tsunami, the water level in the Selangor Dam has steadily fallen to less than 40 percent.

Six months ago, the dam operators commissioned a series of soil tests, worried that underground water will cause disastrous erosion in areas downstream of the dam. Rumors abound that there are serious technical problems with the dam's outlet pipes, and that water has been leaking out at an alarming rate.

And now the Selangor Infrastructure and Public Facilities Permanent Committee (as reported in The Sun and The Star on Sept 16) has acknowledged that the Selangor dam is at the "caution level" of 40 percent after an unseasonal dry spell. This nullifies the 'original' purpose of the dam, which was to offset the hazards of drought.

The Selangor Infrastructure and Public Facilities Permanent Committee is "monitoring" the water level and will implement water rationing when the water level goes lower than 30 percent and is at the "critical" stage. This indicates that the government is just waiting for another 'water crisis' to happen instead of taking early action to plug possible leaks and drastically reduce water consumption.

Committee chairman Abdul Fatah Iskandar concurred that a program to reduce water wastage is needed. However, this would result in a direct conflict of interest, since his committee is working closely with private water supply concessionaires (Splash, Puas and Syabas) whose profits are based on the amount of water they supply.

It is a clear-cut case of corporate versus public interest. As in the case of the Selangor Dam project, corporate interests seem to invariably win.

Will the present 'drought' be used as an excuse to expedite the multi-billion Pahang-Selangor Interstate Water Transfer project, justifying the proposed Kelau Dam in Pahang and a water tunnel across the Titiwangsa Range?

This sort of short-term ‘band-aid solutions’ benefit only the companies awarded construction tenders. It certainly does not address the problem at its source, viz., gross disregard of the ecosystem and criminal mismanagement of our precious natural resources.

[The writers represent SOS Selangor.]


WHY THE SELANGOR DAM?

Destructive Tendencies

20 YEARS DOWN THE LINE

[Originally posted 4 August 2009]