Dealing with known unknowns – and knowns

Preparing for catastrophes and mitigating their impact

By Morand Fachot

Natural and industrial or accidental disasters can take many forms and have devastating human and material consequences. Some may be forecast, others not, and there may be a range of significantly different outcomes. Standardization activities by a number of IEC technical committees (TCs) and subcommittees (SCs) may help warn of impending disasters as well as aid in assessing and mitigating their human and economic impact. 

ShakeAlert warning Example of earthquake early warning issued by ShakeAlert (Image: ShakeAlert via Wikipedia)

Natural, engineering or accidental disasters, a matter of scale

Natural disasters can be considerably deadlier and more destructive than their engineering or industrial equivalents. They may result from weather-related causes (hurricanes, cyclones, storms, floods, heatwaves, blizzards, etc.), or movements at the surface of the earth that may provoke earthquakes, volcanic eruptions or tsunamis.

The December 2004 Indian Ocean earthquake, off the west coast of Sumatra, provoked a series of tsunamis that were directly responsible for the deaths of an estimated 230 000-280 000 people, with many more dying later of infectious diseases. It also injured over 500 000 people and caused tens of thousands to go missing.

The 2010 Haiti earthquake claimed an estimated 220 000 lives, and the 1976 earthquake in Tangshan, China, the deadliest of the 20th century, is estimated to have killed at least 240 000 people, with some placing the toll as high as 700 000.

Natural disasters are also capable of causing extensive damage and of destroying industrial and other man-made structures, thus greatly increasing the impact of the initial event.

In March 2011, an earthquake provoked a tsunami that disabled the Fukushima Daiichi nuclear power plant power supply and cooling systems, resulting in a partial meltdown of some units of the plant. No radiation casualties occurred at the time, but the government ordered the evacuation of over 100 000 people living within a 20-30 km radius of the plant.

In central China in August 1975, heavy rainfall following the Nina typhoon caused the collapse of the Banqiao dam. The resulting massive wave destroyed 60 more dams in its path and killed 25 000 humans, with up to 230 000 dying later of diseases and famine. 

Human and technical factors

Engineering and industrial disasters are often caused by human errors, poor maintenance and the operation of machines and equipment beyond their specifications. Other factors may play their part, such as explosions resulting from certain gases, dusts or vapours coming into contact with a source of heat or a flame in mines, in chemical plants, in paint shops, in the confectionery industry, or in an edifice such as a grain silo, to name only a few places.

The April 1986 Chernobyl nuclear power plant disaster in northern Ukraine was the result of flawed reactor design combined with a number of errors from operators carrying out a test at the plant without taking adequate safety precautions. Some 40 staff and emergency workers died within a few months from radiation-related illnesses, and some 7 000 cases of thyroid cancer in people under 18 at the time of the accident were reported. Thousands more instances of cancer from radiation exposure are likely to be recorded in the future, according to the World Health Organization (WHO).

Direct and indirect costs to Ukraine and Belarus are estimated at several hundreds of billions of dollars over decades.

IEC TC 45: Nuclear instrumentation, and its SCs develop International Standards for a wide range of instrumentation used in the nuclear industry, including control and electrical systems, and of the radiation protection instrumentation that is useful for controlling radiation levels in nuclear power installations, in case of accident, and to prevent the smuggling of radioactive material.

The August 2009 catastrophic failure at the Sayano-Shushenskaya dam, in Siberia, which killed some 75 people, was the consequence of poor maintenance and obsolete equipment being pushed beyond its operating limits, according to the official accident report. This disaster could have been avoided if the plant operators had carried out the necessary maintenance, repair and operations/overhaul (MRO) work. MRO Standards developed by IEC TC 4: Hydraulic turbines, have been central to keeping hydroelectric plants running over many decades in peak condition and improving their capacity.

Explosions in mines and other installations, where potentially explosive gases, flammable liquids and dusts may come into contact with sources of heat or naked flames, can cause large numbers of casualties. IEC TC 31: Equipment for explosive atmospheres, develops and maintains International Standards “relating to equipment for use where there is a hazard due to the possible presence of explosive atmospheres of gases, vapours, mists or combustible dusts”. 

Natural disasters: known unknowns

All of us are aware of the possible occurrence of certain natural disasters, such as earthquakes, or volcanic eruptions. Yet, unlike adverse weather conditions that can sometimes be forecast in advance, these cannot yet be predicted early enough and their intensity cannot be properly assessed to protect people and assets fully from their impact.

Sometimes it is feasible to provide sufficiently early warnings to populations at risk of possible earthquakes and volcanic eruptions. This is possible thanks in part to the work of a number of IEC TCs and SCs.

Earthquakes may afford advance warnings of approaching tremors, which can be detected using various electronic means, including:

  • laser equipment emitting beams that can detect tectonic plates movements. International Standards for equipment (including systems) incorporating lasers are developed by IEC TC 76: Optical radiation safety and laser equipment
  • seismometers which pick up, measure and record vibrations in the Earth’s crust through electronic sensors, including accelerometers, amplifiers and even lasers and interferometers in more modern optically-based devices. International Standards for a variety of sensors used in seismometers (and other devices) are prepared by IEC SC 47E: Discrete semiconductor devices. International Standards for interferometers used for the calibration of optical frequency measurement instruments, are prepared by IEC TC 86: Fibre optics
  • gas detectors which pick up increased levels of radon gas emissions escaping from cracks in the Earth’s crust. International Standards for gas detectors are developed by IEC TC 31: Equipment for explosive atmospheres

An earthquake early warning (EEW) system for the west coast of the United States and called ShakeAlert is being developed and tested by the US Geological Survey (USGS), with a coalition of State and university partners. It could provide “critical seconds of warning time when an earthquake has started and potentially dangerous shaking is imminent”. However, the current US administration plans to cut USD 10 million of federal funding for the system, which would signal its demise.

Volcanic eruptions are easier to predict, owing to the emergence of warning signs such as large numbers of small earth tremors, caused by magma rising through cracks, which can be detected by seismometers. Other warning signs include higher concentrations of certain gases, such as sulphur dioxide, measurable by gas detectors, and higher temperatures around the volcano, which can be detected by infrared thermography cameras. Despite frequent warnings from volcanologists of impending eruptions, authorities often fail to take appropriate measures in a timely way, as was the case in the 1985 eruption of the Nevado del Ruiz volcano in Colombia, which killed 23 000 people. 

Known knowns

In some instances, there may be advance warning of imminent natural disasters, such as typhoons or tsunamis. It can provide the precious time required to prevent the occurrence of the most serious consequences or to mitigate their impact.

Early warning weather stations can alert populations and the authorities by reporting potentially severe conditions in regions where typhoons, storms and hurricanes are frequent.   

In recent years, tsunami warning systems (TWSs) have played an important role in detecting tsunamis in advance and issuing warnings to prevent loss of life and damage. The US National Tsunami Hazard Mitigation Program, led by the National Oceanic and Atmospheric Administration (NOAA), has demonstrated that distant tsunami detection is possible in deep water (up to 6 000 m), making it possible “to quickly confirm potentially destructive tsunamis or, more commonly, eliminate unnecessary evacuations”.

NOAA started deploying its Deep-ocean Assessment and Reporting of Tsunamis (DART®) system in 2004. It reported in 2011 that “tsunami impacts have been predicted [between 2004 and 2011] for 33 tsunamis detected in the deep-ocean with about 80% accuracy when observations and predictions at tide gauges are compared”.

The DART® Easy to Deploy (ETD) system, which is flexible and cost-effective, consists of two elements. A unit anchored to the bottom of the sea is fitted with pressure sensors capable of detecting earth tremors, acoustic transducers and batteries. This unit transmits data to a surface buoy equipped with acoustic transducers to receive that data. The buoy also has electronic systems, batteries and antennas to further uplink the data to satellites. International Standards for underwater acoustics transducers are developed by IEC TC 87: Ultrasonics. The second component of the system is a communications infrastructure needed to issue timely alarms to permit evacuation of the coastal areas.

This system only works when local alert networks are effective in communicating tsunami warnings.

Standardization work from a number of IEC TCs and SCs can prevent the occurrence of many industrial and accidental catastrophes. The problem is more complex for natural catastrophes, but IEC International Standards may help to provide early warnings of impending disasters and mitigate their impact, up to a point.

Gallery
How the DART system works The DART system makes distant tsunami detection possible in deep water (Image: NOAA)
Earthquake warning system ShakeAlert ShakeAlert, an earthquake early warning system for the West Coast of the US, is currently being developed and tested (Image: ShakeAlert)
ShakeAlert warning Example of warning issued by ShakeAlert (Image: ShakeAlert via Wikipedia)