Another year passed

Because of the horrific events at the end of 2004, this is not a time to celebrate geoscientific achievements during the year that has passed.

The horror of Boxing Day

Unlike the collapse of Manhattan’s Twin Towers on 11 September 2001 the world’s cameras were unable to focus on the minutiae of terrible events around the rim of the northern Indian Ocean.  They did not catch the sudden dawning of fear, but the tsunamis of 26 December 2004 were witnessed by millions of coast dwellers in Indonesia, SW Thailand, Sri Lanka, eastern India and as far away as Somalia, Tanzania and Kenya.  At the time of writing the death toll had reached 150 thousand, but it will rise inexorably, and countless people’s lives will be blighted for years to come.  The world did change on Boxing Day 2004 in a way that dwarfs the events of “9/11”.  The majority of those swept in minutes into a debris-loaded sea were among the poorest of their communities, and the dead are dominated by children and old people who simply did not have the strength to save themselves.  News came first from popular tourist resorts dotted on palm-fringed beaches, through cell phones and from hastily shot videos of what must at first have seemed a curiosity.  Before great waves appeared, the sea drew back to leave fish flapping on beaches, which local children rushed to gather as an unexpected benefice.  Ocean waves driven by great seismic events have immense wavelengths, so previously unseen sea floor lingered for 10 to 20 minutes before devastating surges suddenly rose above the horizon..

Off the western coast of Sumatra, a subduction-zone thrust displaced the sea floor by several metres, into which an unimaginable tonnage of ocean rushed.  Its rebound set in motion the most devastating natural phenomena, yet on the open ocean their passage would have been imperceptible because of their broad wavelength.  Unlike wind-waves, tsunamis travel extremely fast, around 400 km per hour; they are seismic disturbances affecting the entire water body.  The further they travel the greater the volume they affect, so they dissipate with distance.  Two days after the initial shock, sea-level rose perceptibly in California, half a world away.  When tsunamis meet shallows, the frictional effect causes the wave to slow, rise and steepen.  The wave breaks far offshore in shallow water, resulting in a surge that rises inexorably on land.  It rips up sea-floor materials, including boulders where they are present.  Damage and deaths result mainly from the backwash that can rip debris and victims several kilometres out to sea, until the next tsunami arrives, and in this case there were at least three.  We have all seen the aftermath, like nuclear devastation but not sterile.  Debris, rotting flesh and sewage breed disease, and as many may die from cholera, insect-borne disease and exposure as perished on Boxing Day morning.

The magnitude of the Sumatran sea-quake was 9.0 on the Richter Scale.  That is a logarithmic measure of the ground displacement, so that for every increase of 1.0 in magnitude ground motion increases by 10 times.  However, it is the energy released that damages and the corresponding increase is 32 times.  The Sumatran sea-quake was the largest recorded since that off Alaska in 1964 (magnitude 9.2) and the fourth largest in a century.  Tsunamis generated off Alaska reached a height of over 60 metres close to the epicentre, but they travelled parallel to the coast of the Americas and caused only 130 deaths.  Those of 26 December 2004 hit land head on, and there are large, densely populated coastal tracts around the Indian Ocean that are below 10 m above mean sea level.  Buildings, particularly for poor people, are fragile and lightweight, so the devastation was almost total, unlike the effects of on-land earthquakes.  In their case, single-storey dwellings that are little more than wood and grass structures cause less deaths than in areas with multi-storey dwellings made of stone or concrete, and the effects are localised.

The US National Oceanographic and Atmospheric Administration (NOAA) is responsible for tsunamis warnings for the eastern Pacific (http://wcatwc.gov/), which are issued in the same way as extreme weather warnings.  Other organisations maintain a permanent watch and warning service for the entire Pacific basin, which is surrounded by the majority of the world’s large earthquake zones, mainly connected to subduction, and is the most prone to tsunamis.  Using bathymetry and landmasses, it is possible to model in detail the wavefronts of tsunamis and their travel times for any circum-Pacific earthquake.  So adequate warning is possible for most coastal areas following a major earthquake.  The Indian Ocean has only one major, tectonically dangerous plate margin, where the Indian Plate drives beneath Eurasia to form the Sunda Trench off the Indonesian archipelago.  Although discussed as recently as mid-2004, no tsunami-warning service is in place for the Indian Ocean.  One reason given for this lack of foresight is that the north-western part of the Sunda Arc has had little major seismicity for more than 150 years.  Therein lay the danger; subduction was locked and a major earthquake grew more likely the longer the quiescence lasted.   All the world’s seismic observatories recorded the massive disturbance and the exact location of the Sumatran event within minutes of its occurrence, but no warnings were issued.  The tsunamis arrived in Sri Lanka and India over 4 hours later, though within less than half an hour in Thailand and Sumatra, which were most devastated.  For the millions whose lives have ended or are in ruins, the greatest advance in the geosciences, plate tectonics, utterly failed them.

What is to be done?

Many geoscientists take pride (and a fair amount of public funding) in focusing their research on dangerous natural phenomena, supposedly aimed at giving warnings or mitigating their effects.   Take any natural calamity, whether it be earthquake or tsunami, volcanic eruption, mudslide, flood or even something so simple as helping provide clean water for the victims of drought or displacement by conflict.  Now list the lives saved by the direct efforts of geoscientists against the torrent of their publications and attendances at conferences.  Is there any cause for pride in the instrumentation, the theory and the field experience?  Or should we reflect on the hubris of scientific endeavour in the aftermath of such awful events?  Two days after the disaster struck I put together detailed topographic elevation data (from the Shuttle Radar Topography Mission – SRTM) for the coastlines that surround the Indian Ocean.  I had had them for 6 months, but did nothing except make some pretty maps for a conference presentation.  I had known what potential they have for predicting areas of flooding, and more important where refuges from inundation might be, but I found “better” things to do.  All coastal areas below 15 m elevation are at risk, and a great many correlate with the tsunamis’ worst effects.  What we could have done and what we did do generally emerge only in retrospect, and indulging in mea culpa serves no purpose.  Individuals have their own agendas, and they are rarely useful in any wider sphere.  The organisations that draw scientists together are not in themselves altruistic, but serve largely academic ends.  However, human tragedies surely remind us of a wider set of responsibilities, even if only momentarily.

A collective organisation of both knowledge and real needs, which sets aside career and the “advancement of science”, is probably the only means of putting the geosciences to work for fully human benefit.  For 40 years such a collective existed in the small form of the Association of Geoscientists for International Development (AGID), which aimed at knowledge transfer from its members to less fortunate areas.  For the latter half of its existence, AGID was subsidised by the Canadian International Development Agency.  A handful of members met at the 32nd International Geological Congress in Florence during late August 2004, the agenda being wholly about its survival or winding up following CIDA’s withdrawal of financial support.  The vote went for continuation.  But, despite helping some young geoscientists of the “Third World” make progress, AGID’s small size and limited aims and funding have proved unable to make it a force that matches real needs or the geosciences’ potential for assisting development.  Data and theory now present the opportunity to resolve two great challenges: giving every man, woman and child on the planet access to safe drinking water; and predicting and mitigating all natural hazards.  Every senior politician in the developed world pays lip service to both, each UN agency convenes to discuss them on a regular basis, and the International Union of Geological Sciences (IUGS) has proposed the International Year of Planet Earth (2005-2007) with those themes at the top of its agenda.  IGC-32, the largest ever gathering of geoscientists was dominated by humanitarian themes and the launch of the IUGS initiative. The International Year of Planet Earth was supposed to have been proposed by the Peoples’ Republic of China at the September 2004 UN General Assembly 59.  It does not appear on the UN web site, and the supporting web site www.esfs.org gives no news of its adoption. But there have been many “Years of…” and even several “Decades of…” from which we have yet to see any tangible outcomes, and little of the “awareness” that they are supposed to generate, certainly not in those areas of the world towards which they were directed.

One collective of professionals that has had a powerful impact on emergencies since 1971 is Médicins sans Frontières (www.msf.org), founded and administered independently of the world’s “great and good”.  Would a geosciences equivalent be feasible and supported?  Yet there are measures that even individuals can take.  At a UN Office for Outer Space Affairs meeting on the use of satellite data for mitigating disasters (Munich, 18-21 October 2004) www.zki.caf.dlr.de/events/2004/unoosa_workshop/unoosa_programme_en.html – Margaret Andrews Deller of the UK Open University presented her ideas (see link at the above web site) on a simple and low-cost way to reduce the impact of natural disasters.  Briefly, she based her suggestions on indigenous people’s deep knowledge of their surroundings.  Recognising that, it should be possible to provide communities with graphic images that highlight potential threats, in forms that are low-cost and easily understood by anyone, such as the use of images that incorporate perspective and show features in near-natural colours.  Her most important point is that such information would not be just a warning, but a means of showing people their homeland in a way that they can learn from and value. That would bring together those affected with those who come to their aid, should catastrophe strike, and would empower local people to take charge of their lives instead of being victims.

Easily understood information and advice is vital for potential victims of catastrophes, and a quick search of the internet reveals lots on all manner of hazards and how to avoid them.  NOAA’s tsunamis website http://wcatwc.gov/ is an excellent example.  Such information needs to be recast into forms that people outside the “information society” can easily understand, and to be distributed – not such a massive task.  What drew children to south Asian beaches on Boxing Day, the massive withdrawal of the sea, is the first sign of a tsunami.  On Pacific islands everyone knows what threat such a weird occurrence signifies, but nobody on the rim of the Indian Ocean did.  But isn’t it also essential for geoscientists to donate some of their publicly and industrially funded time to share their expertise directly with those so much less fortunate than ourselves?  Without that, our claim to be resolving humanity’s problems is a transparent sham.

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