Source properties of the 17 July 1998 Papua New Guinea tsunami based on tide gauge records
Source properties of the 17 July 1998 Papua New Guinea tsunami based on tide gauge records
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根据验潮仪记录得出的 1998 年 7 月 17 日巴布亚新几内亚海啸的来源特性
DOI：
10.1093/gji/ggv145
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发表时间：
2015
期刊：
影响因子：
--
通讯作者：
M. and K. Satake
中科院分区：
文献类型：
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作者：
Heidarzadeh;M. and K. Satake
我们分析了 1998 年 7 月 17 日巴布亚新几内亚 (PNG) 海啸的四份新检索到的验潮仪记录，以研究这次海啸的统计和光谱特性。四个验潮记录来自距离源头 600-1450 公里的隆布鲁姆 (PNG)、拉包尔 (PNG)、马拉卡勒岛 (帕劳) 和雅浦岛 (雅浦州) 站。根据这些测量仪，海啸记录的最大波谷到波峰高度为 3-9 厘米。光谱分析显示在 2-4 分钟和 6-20 分钟的周期带有两个主峰，在~5 分钟的周期有明显的分离。我们将这些高峰期分别解释为巴布亚新几内亚海啸的山体滑坡和地震源。海啸波形分析显示，与主震的起源时间相比，滑坡发生延迟了 12-17 分钟。包括这种延迟在内的数值模拟相当准确地再现了观测到的验潮仪记录。这是 1998 年巴布亚新几内亚海啸延迟滑坡源的第一个直接证据，之前是根据声学 T 相记录间接估计的。
We analysed four newly retrieved tide gauge records of the 1998 July 17 Papua New Guinea (PNG) tsunami to study statistical and spectral properties of this tsunami. The four tide gauge records were from Lombrum (PNG), Rabaul (PNG), Malakal Island (Palau) and Yap Island (State of Yap) stations located 600–1450 km from the source. The tsunami registered a maximum trough-to-crest wave height of 3–9 cm at these gauges. Spectral analysis showed two dominant peaks at period bands of 2–4 and 6–20 min with a clear separation at the period of ∼5 min. We interpreted these peak periods as belonging to the landslide and earthquake sources of the PNG tsunami, respectively. Analysis of the tsunami waveforms revealed 12–17 min delay in landslide generation compared to the origin time of the main shock. Numerical simulations including this delay fairly reproduced the observed tide gauge records. This is the first direct evidence of the delayed landslide source of the 1998 PNG tsunami which was previously indirectly estimated from acoustic T-phase records.