Tide Gauge Observations of 2004–2007 Indian Ocean Tsunamis from Sri Lanka and Western Australia
Tide Gauge Observations of 2004–2007 Indian Ocean Tsunamis from Sri Lanka and Western Australia
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DOI：
10.1007/s00024-008-0434-5
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发表时间：
2009-02
影响因子：
2
通讯作者：
C. Pattiaratchi;E. M. Sarath Wijeratne
中科院分区：
文献类型：
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作者：
C. Pattiaratchi;E. M. Sarath Wijeratne
对2004年12月、2005年3月、2006年7月和2007年9月印度洋海啸期间从斯里兰卡(3个站)和西澳大利亚州(11个站)收集的验潮仪数据进行了检查，以确定这些事件期间的海啸行为。在2004年12月的海啸期间，科伦坡(斯里兰卡)和本伯里(西澳大利亚)分别录得3.87米和1.75米的最大浪高。结果表明，虽然海啸的相对强度不同，但每个测站的海啸行为是相似的。这是由于当地和区域地形的影响。在所有潮汐测量仪上，对应于20到85分钟之间的周期的光谱能量在海啸期间都有所增加。从斯里兰卡西海岸和南海岸(科伦坡和基林达)获得的海平面数据表明，马尔代夫岛链的海浪反射十分重要，在第一波到达后2至3小时产生了最大海浪。相比之下，东海岸的亭可马里没有显示出反射波的证据。同样，在澳大利亚西海岸，最高浪出现在第一波到达后15个小时。在这里，根据旅行时间，我们假设海浪是从马斯卡林山脊和/或马达加斯加岛反射过来的。在2006年的海啸中没有反射波，主波从地形特征传播开来。海啸的主要影响之一是在当地的共振频率上建立了振荡。由于斯里兰卡和西澳大利亚州的海岸线相对较直，这些振荡与大陆架振荡的基本周期有关。对于科伦坡，这相当于75分钟的周期，而在杰拉尔顿和巴塞尔顿(澳大利亚)，4小时的周期最为突出；在朱利安湾和弗里曼特尔，共振周期为2.7小时。
Tide gauge data collected from Sri Lanka (three stations) and Western Australia (eleven stations) during the Indian Ocean tsunamis, which occurred in December 2004, March 2005, July 2006, and September 2007, and incorporated five tsunamis, were examined to determine tsunami behaviour during these events. During the December 2004 tsunami, maximum wave heights of 3.87 m and 1.75 m were recorded at Colombo (Sri Lanka) and Bunbury (Western Australia), respectively. The results indicated that although the relative magnitudes of the tsunamis varied, the tsunami behaviour at each station was similar. This was due to the effect of the local and regional topography. At all tide gauges, the spectral energy corresponding to periods between 20 and 85 minutes increased during the tsunami. The sea-level data obtained from the west and south coasts of Sri Lanka (Colombo and Kirinda) indicated the importance of wave reflections from the Maldives Island chain, which produced the maximum wave two to three hours after the arrival of the first wave. In contrast, Trincomalee on the east coast did not show evidence of a reflected wave. Similarly, along the west coast of Australia, the highest waves occurred 15 hours after the arrival of the first wave. Here, based on travel times, we postulated that the waves were reflected from the Mascarene Ridge and/or the Island of Madagascar. Reflected waves were not present in the 2006 tsunami, where the primary waves propagated away from topographic features. One of the main influences of the tsunami was to set up oscillations at the local resonance frequency. Because Sri Lanka and Western Australia have relatively straight coastlines, these oscillations were related to the fundamental period of the shelf oscillation. For Colombo, this corresponded to 75-minute period, whereas in Geraldton and Busselton (Australia), the four-hour period was most prominent; at Jurien Bay and Fremantle, the resonance period was 2.7 hours.