Evaluation of the ability of a cargo-ship GNSS network to detect tsunamis in the Solomon Islands region

The southwest Pacific Region regularly produces tsunamis triggered by strong earthquakes of magnitude up to M8.1 associated to its complex tectonics and subduction processes. According to the NOAA/NCEI database, these tsunamis represent about one quarter of the tsunamis recorded worldwide. Some of them have been catastrophic for coastal populations in terms of the number of dead and injured and destructions of infrastructures or agriculture land. For example, the 2007 Solomon Islands & the 2009 Samoa tsunamis killed 50 and 192 people, respectively and did hundreds of millions of US dollars in damage. The present study focuses on the Solomon Islands which has suffered from several recent destructive tsunamis, including the tsunami in 2007, and a doublet tsunami in 2016. Only a few tide gauges and 2 Australian DART captured the tsunami signal, demonstrating the need for more densely spaced observations and direct measurements from the ocean, in order to improve the warning procedures, reducing the alert timing. One way to increase this observing capacity is to fill the geodetic observation gap in the ocean using a network of cargo-ships equipped with GNSS systems tracking anomalous variations of the sea-level. These measurements can potentially detect tsunamis of different origins. To complete the few available studies focusing on the Solomon Islands tsunamis, the project aims (i) to model the 2007 and 2016 tsunamis using the records/observations on land or close to the shore (e.g., seismic network, land-based GNSS and tide-gauges data), (ii) to compare their source and impact on population and infrastructure, (iii) to analyze what a constantly moving cargo-ship GNSS network might experience in terms of tsunami travel time and tsunami predicted amplitudes, and (iv) to determine how useful such a cargo-ship GNSS network would be to increase our ability to detect and respond to these hazards through local early warning. By exploring the relationship between tsunami sources, travel times and amplitudes using ships’ locations, the study seeks to determine the ability of a defined regional ship network to function as a low-cost method to improve the detection of tsunamis, and to improve effective warnings and hazard mitigation for coastal areas and the exposed communities in the region.