- Feature Article by Dr Rashmin Gunasekera for Rotary Club of Colombo Central - </head> <body bgcolor="#ffffff"> <table width="981" border="0" cellspacing="0" cellpadding="0" cool gridx="16" gridy="16" height="6251" showgridx showgridy usegridx usegridy> <tr height="208"> <td width="980" height="208" colspan="5" valign="top" align="left" xpos="0"><img src="../images/rotarybanner-for-web.jpg" alt="" height="200" width="980" border="0"></td> <td width="1" height="208"><spacer type="block" width="1" height="208"></td> </tr> <tr height="6025"> <td width="16" height="6025"></td> <td content csheight="6025" width="944" height="6025" colspan="3" valign="top" xpos="16"> <div align="center"> <p><font size="+2" face="Verdana, Arial, Helvetica, sans-serif">Tsunami Wars: Forewarned is Forearmed</font></p> </div> <div> <p><font size="-1" face="Verdana, Arial, Helvetica, sans-serif"> </font></p> </div> <div align="center"> <h3><font size="-1" face="Verdana, Arial, Helvetica, sans-serif">Dr. Rashmin Gunasekera</font></h3> <p><font size="-1" face="Verdana, Arial, Helvetica, sans-serif">E mail: Rashmin@dunelm.org.uk</font></p> <p><font size="-1" face="Verdana, Arial, Helvetica, sans-serif"> </font></p> <p><font size="-1" face="Verdana, Arial, Helvetica, sans-serif">“The high hills and forests shook under the immortal feet of the descending god, the earthshaker, POSEIDON. Dressed in gold, he picked up his splendid golden whip, mounted his chariot and drove across the waves.”</font></p> <p><font size="-1" face="Verdana, Arial, Helvetica, sans-serif">- Homer, The Iliad</font></p> </div> <div> <p><font size="-1" face="Verdana, Arial, Helvetica, sans-serif"> </font></p> <h3><font size="-1" face="Verdana, Arial, Helvetica, sans-serif">Introduction to tsunamis</font></h3> </div> <div align="justify"> <p><br> <font size="-1" face="Verdana, Arial, Helvetica, sans-serif">Ever since 26th of December 2004, Sri Lanka has been hurled not only into a situation of devastation beyond imagination, but also into a maelstrom of confusion. A natural disaster on such a terrifying scale has not impacted on the country in living memory, and consequently, misunderstandings and misconceptions have run rife in the aftermath on the nature “phenomenon” of the tsunami. We cannot prevent tsunamis, as they are a fact of life and are bound reoccur. However, by understanding tsunamis better (which is what this article aims to achieve), we could reduce the damage done by future pervasive tsunamis and reduce human vulnerability. This article represents an initial step in that process of learning and comprehension.</font><br> <br> <font size="-1" face="Verdana, Arial, Helvetica, sans-serif">Although tsunamis are often mistakenly referred to as tidal waves, they have nothing to do with tides, which we know are regulated by the gravitational attraction of extraterrestrial objects such as the sun and the moon. To be precise, a tsunami is an impulsive sea wave triggered by a submarine (undersea) disturbance (usually an earthquake). Tsunami actually means “great harbour wave” in Japanese, because of the wave amplification seen in bays and harbours. The actual behaviour of tsunamis and tidal waves differ radically.</font><br> <br> </p> <h3><font size="-1" face="Verdana, Arial, Helvetica, sans-serif">Tsunami: the genesis</font></h3> </div> <div> <h3><b><font size="-1" face="Verdana, Arial, Helvetica, sans-serif">What causes a tsunami?</font></b></h3> </div> <div align="justify"> <p><font size="-1" face="Verdana, Arial, Helvetica, sans-serif">Most tsunamis are caused by the sudden uplift or subsidence of the seafloor triggered by a submarine earthquake. Most tsunami triggering earthquakes (tsunamigenic earthquakes) do tend to occur in “subduction zones”.</font></p> <p><font size="-1" face="Verdana, Arial, Helvetica, sans-serif">A subduction zone is an area where two or more of the Earth’s tectonic plates (fragments of the earth’s crust that are continually in motion) converge and the denser (usually oceanic) plate subsides (slides) under the less dense (usually continental) plate as illustrated in Figure 1. This displaces, tilts or offsets a large area of the ocean floor. During the December 26<sup>th</sup> 2004 earthquake in Aceh, Indonesia, the Indian oceanic plate subsiding under the continental Burma plate caused friction between the plates, which in turn triggered an earthquake.</font></p> <p><font size="-1" face="Verdana, Arial, Helvetica, sans-serif">This released tremendous energy, equivalent to that released by many nuclear bombs, which was imparted to the overlying body of water causing the onset of the tsunami. It is noteworthy that most submarine earthquakes do <i>not </i>generate tsunamis: along the west coast of South America, a region where tsunamis are most prominent, only 20 tsunamis have been recorded from a possible 1098 offshore earthquakes (Bryant, E., 2001). This is because earthquake-induced destructive tsunamis require at least 2 conditions: i) a shallow crustal depth (< 40 km) at which the earthquake to occurs, and ii) an earthquake with a magnitude greater than 6.0 on the Richter scale.</font></p> <p><font size="-1" face="Verdana, Arial, Helvetica, sans-serif">Another cause of tsunamis are volcanic eruptions that lead from, volcano-induced earthquakes, large ash flows and partial collapse of volcanoes such as in Santorini, Italy in 1470 BC and Krakatau in Indonesia in 1883 AD. Other causes of tsunamis include large underwater landslides, meteorite impacts and extreme meteorological events that lead to local tsunamis.</font></p> </div> <div> <p><font size="-1" face="Verdana, Arial, Helvetica, sans-serif"> </font></p> <h3><b><font size="-1" face="Verdana, Arial, Helvetica, sans-serif">Where do most tsunamis occur?</font></b></h3> </div> <div align="justify"> <p><font size="-1" face="Verdana, Arial, Helvetica, sans-serif">As the rim of the Pacific Ocean is almost surrounded by large subduction zones, this area experiences some of the world’s greatest earthquakes and hosts some of the most explosive volcanoes. As a result, over 80% of the most significant tsunamis occur in this region. The Mediterranean and Caribbean Seas to a lesser extent (approximately 15%) have also been affected by tsunamis. The tsunami threat is most acute along the coasts of Alaska, Russia, Philippines, Indonesia, the western seaboard of South and Central America and Japan. The tsunami that swept through Ryukyu Islands, south of Japan in 1971 had a wave height of approximately 90 m. In comparison, the reported tsunami wave height near Galle in 2004 was only approximately 3.5 m.</font></p> </div> <div> <p><font size="-1" face="Verdana, Arial, Helvetica, sans-serif"> </font></p> <h3><b><font size="-1" face="Verdana, Arial, Helvetica, sans-serif">How does a tsunami operate?</font></b></h3> </div> <div align="justify"> <p><font size="-1" face="Verdana, Arial, Helvetica, sans-serif">Most tsunamis generated by large earthquakes travel in wave trains that may contain several large waves. A tsunami travelling towards a distant shore will travel across the deep ocean and then across the continental shelf (as shown in Figure 2) before reaching the shoreline. These waves in the deep ocean are difficult to identify as their wave height is less than 0.4 m.</font></p> <p><font size="-1" face="Verdana, Arial, Helvetica, sans-serif">Crucially, tsunamis have very long wavelengths (distance between two crests of the wave) that range from 10 to 500 km in deep oceans, and this is what distinguishes them from tidal waves and storm surges. This exceptionally long wavelength, which is a result of the earthquake generating mechanism, allows tsunamis to travel across oceans without losing energy and at great speeds. Therefore, with greater ocean depth, the tsunami achieves greater speed – up to 700 km/hr.</font></p> <p><font size="-1" face="Verdana, Arial, Helvetica, sans-serif">When the tsunami wave crosses the continental shelf and approaches the shore, the shape of the waveform alters from a sinusoidal (normal) waveform to a wave with a sharp peak (mathematically known as a Stokes wave) and the trough or bottom of the wave flattens due to the large wave period (the time between two crests of the wave). Tsunamis tend to have wave periods of usually 10 to 45 minutes. The significance of this change in wave shape is that when the wave approaches the coastline, the bottom part of the wave slows down on the increasingly shallow ocean floor, which has the effect of drawing the shoreline out to sea. This is why the sea appears to initially retreat.</font></p> <p><font size="-1" face="Verdana, Arial, Helvetica, sans-serif">At this stage, the peak of the wave sharpens and continues at a much higher speed, usually around 50 to 60 km/hr near the shore. To accommodate this difference in speed the wave increases in height and, due to the large distances in wavelength, the bottom part of the wave lags further behind to form a wave travelling wholly <i>above</i> sea level that has the potential to carry large amounts of water. It is precisely this difference in speeds, between the top and the bottom of the wave, that creates the effect of the incoming wave seeming like “a wall of water”. However, it is not clear which of the several waves will have the most destructive impact on the coast.</font></p> </div> <div> <p><font size="-1" face="Verdana, Arial, Helvetica, sans-serif"> </font></p> <h3><font size="-1" face="Verdana, Arial, Helvetica, sans-serif">Destructive power of a tsunami</font></h3> </div> <div align="justify"> <p><font size="-1" face="Verdana, Arial, Helvetica, sans-serif">The destructive power of a tsunami is related to area inundated, wave impact and erosion. The severity of the wave impact is a result of several factors that include topography of the seabed, morphology of the coastline which relates to the dissipation of the energy of the tsunami and direction of travel of the tsunami. Areas that would bear the greatest impact of a tsunami are shores perpendicular to the direction of the wave front of the tsunami, with long gentle slopes and concave in shape like bays or harbours. Bays and harbours tend to focus the energy of a tsunami. Also, if the tsunami wave period tends to approximate to some harmonic of the natural frequency of that basin, it could cause resonance and increase the destructiveness of the tsunami. Tsunami waves that arrive at high tide and causes refraction have boosted destructiveness.</font></p> <p><font size="-1" face="Verdana, Arial, Helvetica, sans-serif">Although barrier reefs reduce the degree of hazard, if there is a gap in the reef, the shore becomes exposed and that locality would be at a much higher risk due to the concentration of the wave energy. At its peak, the December 26<sup>th</sup> 2004 tsunami would have deposited approximately 100,000 tonnes of seawater for every 1.5 m of coastline. Therefore, the most important parameter for hazard evaluation from tsunamis is the extent of “run up”, which is the maximum height of a tsunami when it reaches the shore. It is accepted within the scientific community that tsunamis with more than 1 m of run up are deemed very dangerous.</font></p> <p><font size="-1" face="Verdana, Arial, Helvetica, sans-serif">In broad terms the cross-sectional area inundated by a tsunami on land is equivalent to the cross-sectional area of water carried under the wave crest of the tsunami in the proximity of the shore, i.e., the black areas in Figure 3 are equivalent. This allows scientists to relate the maximum distance of flooding with the run up height of a tsunami. This is a very useful indicator for civil defence authorities. The after effects of a tsunami involve both receding and invasive phases, much like water sloshing to and fro in a bowl. On average the danger period of a tsunami could last from to 4 to 5 hours.</font></p> <p><font size="-1" face="Verdana, Arial, Helvetica, sans-serif">The turbulent swirl patterns of the tsunami observed near Kalutara on December 26<sup>th</sup> 2004 are not totally understood by the scientific community. A possible explanation might be that they were an artefact of hydro-dynamical action between the interaction of the tsunami and an oblique wave leading to flow impingement and semi-vortex formation.</font></p> </div> <div> <p><font size="-1" face="Verdana, Arial, Helvetica, sans-serif"> </font></p> <h3><font size="-1" face="Verdana, Arial, Helvetica, sans-serif">Potential future threats of tsunamis to Sri Lanka</font></h3> </div> <div align="justify"> <p><font size="-1" face="Verdana, Arial, Helvetica, sans-serif">Having established the dynamics of tsunamis, we can now turn our attention to taking concrete steps to defend ourselves from their destructive power. To implement this, three stages of preparation are required: i) monitoring, ii) warning and iii) preparedness.</font></p> <p><font size="-1" face="Verdana, Arial, Helvetica, sans-serif">According to the National Geophysical Data Centre (NGDC) that catalogues tsunami events, within the last 250 years there have been in excess of 60 tsunamis in the Indian Ocean region. Therefore, tsunamis are not that infrequent in the Indian Ocean.</font></p> <p><font size="-1" face="Verdana, Arial, Helvetica, sans-serif">The source locations of these tsunamis as seen by Figure 4 shows that their spatial distribution is strongly related to the seismic activity of the region. The number of possible run ups that each of these tsunamis incurred illustrates their respective spatial extent and intensities. It is also clear from Figure 4 that most of the tsunamis only had a local impact. Out of these 60 events, only 3 tsunamis affected Sri Lanka including the December 26<sup>th</sup> 2004 tsunami. The previous two tsunamis occurred on December 31<sup>st</sup> 1881 and in August 27<sup>th</sup> 1883. The former was an earthquake-induced tsunami that originated from the bay of Bengal and the latter was a result of the highly explosive eruption of Krakatau volcano in Indonesia.</font></p> <p><font size="-1" face="Verdana, Arial, Helvetica, sans-serif">Needless to say, the December 26<sup>th</sup> 2004 tsunami was the largest in the Indian Ocean. The earthquake that triggered this tsunami was the 5<sup>th</sup> largest earthquake ever recorded and the energy it dissipated was equivalent to 30,000 Hiroshima type bombs. It was so powerful that it caused the whole earth to resonate. Prior to the December 26<sup>th</sup> 2004 tsunami, the last destructive tsunami in the Indian Ocean occurred on June 2<sup>nd</sup> 1994, which inundated several villages in the islands of Java and Bali, Indonesia and led to over 250 casualties.</font></p> </div> <div> <p><font size="-1" face="Verdana, Arial, Helvetica, sans-serif"> </font></p> <h3><font size="-1" face="Verdana, Arial, Helvetica, sans-serif">Where will the next destructive tsunami originate?</font></h3> </div> <div align="justify"> <p><font size="-1" face="Verdana, Arial, Helvetica, sans-serif">In the Indian ocean, tsunamigenic earthquakes could occur in any of the possible 3 regions: a) mostly off the coast of Sumatra b) 70-100 km south of the Kutch region of Pakistan and c) the bay of Bengal (Figure 4). Figure 4 also shows the epicentres of events greater than Richter magnitude 6.0 (earthquakes that could cause tsunamis) in and around the central and eastern parts of the Indian Ocean as recorded by the US Geological Survey since 1973.</font></p> <p><font size="-1" face="Verdana, Arial, Helvetica, sans-serif">The 88 events recorded are mostly concentrated off the shore of Sumatra, Indonesia along the area called the Sundra trench. During this time, there have been 8 tsunamis in the Indian Ocean region. As most tsunamis are earthquake induced, it is reasonable to expect that the next possible destructive tsunami that might strike Sri Lanka would also originate off the coast of Sumatra.</font></p> <p><font size="-1" face="Verdana, Arial, Helvetica, sans-serif">The potential for future destructive tsunamis from this region is still great as the December 26<sup>th</sup> 2004 Aceh earthquake did not relieve all the stress along the faults at the Sundra trench. This fault system is still highly stressed. Furthermore, the large displacement caused by the earthquake has heightened the stress of the neighbouring faults. Past global seismic activity do suggest after such powerful earthquakes, other large earthquakes do follow. Therefore, it would be very useful to conduct a quantitative study and evaluate whether the statistical probability has increased of another big earthquake in the region since December 2004.</font></p> <p><font size="-1" face="Verdana, Arial, Helvetica, sans-serif">The other distinct possible source for a destructive tsunami in the Indian Ocean might be the collapse of the unstable south flank of Krakatau volcano, Indonesia. However, broad global tsunami patterns do indicate that each region of the world has its own cycle of frequency and pattern in generating tsunamis. These tsunamis could vary significantly in size from small to large and highly destructive ones.</font></p> </div> <div> <p></p> <h3><font size="-1" face="Verdana, Arial, Helvetica, sans-serif">What will a tsunami monitoring system achieve?</font></h3> </div> <div align="justify"> <p><font size="-1" face="Verdana, Arial, Helvetica, sans-serif">The role of a tsunami-monitoring centre is to notify and alert local warning centres to prompt civil defence actions against an oncoming tsunami. To achieve this purpose, a monitoring centre must rely on information derived from geophysical instruments such as seismic sensors, ocean-bottom pressure gauges and tide gauges. From global and regional arrays, seismic and oceanographic stations a tsunami monitoring centre can determine accurately the location and magnitude of a tsunamigenic event and evaluate the probability of a tsunami.</font></p> <p><font size="-1" face="Verdana, Arial, Helvetica, sans-serif"> </font><font size="-1" face="Verdana, Arial, Helvetica, sans-serif">If a tsunami has been generated, tsunami warnings are issued to all possible areas of inundation. These warnings include seismic data, potential tsunami wave heights (run ups) and projected impact (travel) times. In turn, local warning stations along coasts could enhance the effectiveness of their warning capabilities, produce tsunami hazard inundation area maps and initial risk assessments and develop localized tsunami hazard mitigation programs including public and community awareness. However, for the Indian Ocean, as destructive tsunamis are infrequent and human memory is surprisingly short, complacency and inefficiency could be the bane of such a system.</font></p> <p><font size="-1" face="Verdana, Arial, Helvetica, sans-serif">Although warning systems would do little to reduce the vulnerability to the near-source area of tsunamis, which might be inundated within minutes of the earthquake occurring, they would have a profound impact in far source areas such as Sri Lanka. Had such a system existed, the death toll from the December 26<sup>th</sup> tsunami in Sri Lanka would probably have been no more than a few 10s of people. It took approximately 110 minutes from the occurrence of the earthquake until the tsunami inundated the coast of Kalmunai, the first region of the impact, in the east coast of Sri Lanka (Figure 5). To eliminate future loss of life on a similar scale, perhaps it might be prudent to contemplate tsunami drills such as earthquake drills in Japan, siren warning systems, telecommunication education and preparedness.</font></p> <p><font size="-1" face="Verdana, Arial, Helvetica, sans-serif">Scientists are also trying to learn by examining the past history of tsunamis (paleo-tsunami studies) by looking at the geological record. However, sometimes there is debate as to how to distinguish storm surge deposits from tsunami deposits. In other studies scientists have established a linear relationship between earthquake moment magnitude, Mw (which relates to the energy released by an earthquake) and the run up of tsunamis. However, these linear relationships differ depending on geographic region and the shape of the coastline.</font></p> <p><font size="-1" face="Verdana, Arial, Helvetica, sans-serif">It is only by understanding the behaviour of a tsunami that we are able to take the most appropriate steps to ensure that should such a natural disaster reoccur, all possible step would have been taken to minimise death and destruction. More scientific investigations into the patterns of tsunami hazard in the Indian Ocean region could prove extremely valuable in mitigating future threats from this up-until-now under estimated natural hazard.</font></p> </div> <div> <p><font size="-1" face="Verdana, Arial, Helvetica, sans-serif"> </font></p> <p><font size="-1" face="Verdana, Arial, Helvetica, sans-serif"> </font></p> <h3><font size="-1" face="Verdana, Arial, Helvetica, sans-serif">Figure captions</font></h3> </div> <div align="justify"> <p><font size="-1" face="Verdana, Arial, Helvetica, sans-serif"><a href="articleTsunami_files/image001.jpg" target="_blank">Figure 1:</a> Schematic representation of a subduction zone, where one plate subsides beneath the other, and giving rise to a large displacement of overlying water resulting in a tsunami (<i>Source</i>: Restless Earth, National Geographic Society).</font></p> <p><font size="-1" face="Verdana, Arial, Helvetica, sans-serif"><a href="articleTsunami_files/image002.jpg" target="_blank">Figure 2:</a> The various phases of a tsunami. Stage I: in the deep ocean travelling as a sinusoidal wave, Stage II: bottom part of the wave slowing down giving rise to a conical shape, and Stage III: at the coast. The tsunami hits the coast as singular wave travelling above mean sea level. The arrow points in the direction of travel of the tsunami wave (<i>Adopted</i> from Bryant, E. (2001)).</font></p> <p><font size="-1" face="Verdana, Arial, Helvetica, sans-serif"><a href="articleTsunami_files/image003.jpg" target="_blank">Figure 3:</a> Relationship between volume and cross-sectional area of the tsunami and the area inundated. This also shows the large volume carried by the wave as a result of the large wavelength (<i>Source:</i> Bryant, E. (2001)).</font></p> <p><font size="-1" face="Verdana, Arial, Helvetica, sans-serif"><a href="articleTsunami_files/image004.jpg" target="_blank">Figure 4:</a> Map of tsunami source locations in the Indian Ocean for the past 250 years (constructed from data provided by the US Geophysical Data Centre). Red circles show the epicentre locations of earthquakes greater than magnitude 6.0 on the Richter scale since 1973 as recorded in the central and eastern parts of the Indian Ocean (Data provided by the US Geological Survey).</font></p> <p><font size="-1" face="Verdana, Arial, Helvetica, sans-serif"><a href="articleTsunami_files/image005.jpg" target="_blank">Figure 5:</a> Adopted animated simulation of the path and time of the December 26<sup>th</sup> 2004 tsunami on its approach and impact on the Sri Lankan coastline. This clearly indicates the mainly unidirectional path of the tsunami. (<i>Source</i>: National Institute of Advanced Industrial Science and Technology, Japan).</font></p> <p></p> </div> <div> <h3><font size="-1" face="Verdana, Arial, Helvetica, sans-serif">References:</font></h3> <p><font size="-1" face="Verdana, Arial, Helvetica, sans-serif">Bryant, E., (2001), Tsunami the underrated hazard, Cambridge Uni. Press., Cambridge.</font></p> <p><font size="-1" face="Verdana, Arial, Helvetica, sans-serif">National Geographic Society, (1997), Restless Earth, National Geographic Society.</font></p> <p><font size="-1" face="Verdana, Arial, Helvetica, sans-serif"> </font></p> <font size="-1" face="Verdana, Arial, Helvetica, sans-serif"><br clear="ALL"> </font> <p><font size="-1" face="Verdana, Arial, Helvetica, sans-serif"> </font></p> <p align="center"><font size="-1" face="Verdana, Arial, Helvetica, sans-serif"> </font></p> <p align="center"><font size="-1" face="Verdana, Arial, Helvetica, sans-serif"><img src="articleTsunami_files/image001.jpg" height="406" width="446" v:shapes="_x0000_i1025"></font></p> <p align="center"><font size="-1" face="Verdana, Arial, Helvetica, sans-serif"> </font></p> </div> <font size="-1" face="Verdana, Arial, Helvetica, sans-serif"><br clear="ALL"> </font> <div> <p align="center"><font size="-1" face="Verdana, Arial, Helvetica, sans-serif"> </font></p> <p align="center"><font size="-1" face="Verdana, Arial, Helvetica, sans-serif"><img src="articleTsunami_files/image002.jpg" height="231" width="893" v:shapes="_x0000_i1026"><br clear="ALL"> <img src="articleTsunami_files/image003.jpg" height="270" width="681" v:shapes="_x0000_i1027"></font></p> <p align="center"><font size="-1" face="Verdana, Arial, Helvetica, sans-serif"> </font></p> <p align="center"><font size="-1" face="Verdana, Arial, Helvetica, sans-serif"> </font></p> <p align="center"><font size="-1" face="Verdana, Arial, Helvetica, sans-serif"> </font></p> <p align="center"><font size="-1" face="Verdana, Arial, Helvetica, sans-serif"> </font></p> </div> <font size="-1" face="Verdana, Arial, Helvetica, sans-serif"><br clear="ALL"> </font> <p align="center"><font size="-1" face="Verdana, Arial, Helvetica, sans-serif"><img src="articleTsunami_files/image004.jpg" height="405" width="416" v:shapes="_x0000_i1028"><br clear="ALL"> </font></p> <p align="center"><font size="-1" face="Verdana, Arial, Helvetica, sans-serif"> </font></p> <p align="center"><font size="-1" face="Verdana, Arial, Helvetica, sans-serif"> </font></p> <p align="center"><font size="-1" face="Verdana, Arial, Helvetica, sans-serif"><img src="articleTsunami_files/image005.jpg" height="175" width="714" v:shapes="_x0000_i1029"></font></p> <p align="center"><font size="-1" face="Verdana, Arial, Helvetica, sans-serif"> </font></p> <p><font size="-1" face="Verdana, Arial, Helvetica, sans-serif"> </font></p> </td> <td width="20" height="6025"></td> <td width="1" height="6025"><spacer type="block" width="1" height="6025"></td> </tr> <tr height="17"> <td width="353" height="17" colspan="2"></td> <td bgcolor="#ccff66" content csheight="17" width="271" height="17" valign="top" xpos="353"> <div align="center"> <font size="-1" face="Verdana, Arial, Helvetica, sans-serif"><a href="../index.htm">Home</a></font></div> </td> <td width="356" height="17" colspan="2"></td> <td width="1" height="17"><spacer type="block" width="1" height="17"></td> </tr> <tr height="1" cntrlrow> <td width="16" height="1"><spacer type="block" width="16" height="1"></td> <td width="337" height="1"><spacer type="block" width="337" height="1"></td> <td width="271" height="1"><spacer type="block" width="271" height="1"></td> <td width="336" height="1"><spacer type="block" width="336" height="1"></td> <td width="20" height="1"><spacer type="block" width="20" height="1"></td> <td width="1" height="1"></td> </tr> </table> <p></p> </body> </html>