# Tsunami Modeling and Satellite-Based Emergency Mapping: Workflow Integration Opportunities
## 2 Materials and Methods: Tsunami Modelling and Satellite-Based Emergency Mapping
### GDACS Tsunami Model Outputs
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16 September 2015 22:56 & 16 September 2015 23:34 & Chigualoco & 7.0 & 31.75\({}^{\circ}\) S & 71.50\({}^{\circ}\) W \\
16 September 2015 22:56 & 16 September 2015 23:10 & Conchali & 4.6 & 31.88\({}^{\circ}\) S & 71.49\({}^{\circ}\) W \\
16 September 2015 22:56 & 16 September 2015 23:08 & Los Vilos & 4.4 & 31.92\({}^{\circ}\) S & 71.51\({}^{\circ}\) W \\
16 September 2015 22:56 & 16 September 2015 23:06 & Huentelauquen & 4.0 & 31.58\({}^{\circ}\) S & 71.53\({}^{\circ}\) W \\
16 September 2015 22:56 & 16 September 2015 23:10 & El Romeral & 3.9 & 32.42\({}^{\circ}\) S & 71.38\({}^{\circ}\) W \\
16 September 2015 22:56 & 16 September 2015 23:02 & Angostura & 3.1 & 31.50\({}^{\circ}\) S & 71.55\({}^{\circ}\) W \\
16 September 2015 22:56 & 16 September 2015 23:04 & Totoralillo & 3.1 & 32.04\({}^{\circ}\) S & 71.52\({}^{\circ}\) W \\
16 September 2015 22:56 & 16 September 2015 23:04 & Quilimari & 2.9 & 32.12\({}^{\circ}\) S & 71.49\({}^{\circ}\) W \\
16 September 2015 22:56 & 16 September 2015 23:04 & Pichidangui & 2.9 & 32.13\({}^{\circ}\) S & 71.53\({}^{\circ}\) W \\
16 September 2015 22:56 & 16 September 2015 23:06 & Ingeniero Santa Maria & 2.6 & 32.23\({}^{\circ}\) S & 71.47\({}^{\circ}\) W \\
16 September 2015 22:56 & 16 September 2015 23:00 & Quillaicillo & 2.6 & 31.41\({}^{\circ}\) S & 71.57\({}^{\circ}\) W \\
16 September 2015 22:56 & 16 September 2015 23:06 & Guaquen & 2.6 & 32.30\({}^{\circ}\) S & 71.45\({}^{\circ}\) W \\
16 September 2015 22:56 & 16 September 2015 23:00 & Mainecillo & 2.5 & 30.99\({}^{\circ}\) S & 71.64\({}^{\circ}\) W \\
16 September 2015 23:02 & 16 September 2015 23:14 & Concon & 2.2 & 32.94\({}^{\circ}\) S & 71.52\({}^{\circ}\) W \\
16 September Validation of the GDACS Tsunami Model: Tidal Gauge and Post-Event Field Survey  
The comparison between measured and calculated sea levels allows the quality of the calculation to be assessed. To this end, expected wave height and sea level measured by tidal gauges are compared in three different locations: Coquimbo, Valparaiso and the Juan Fernandez Island (respectively green triangles 1, 2 and 3 in Figure 4). The comparison of the predicted and measured graphs shows that, although the absolute height of the measured and estimated values seem to mismatch, the main features of the event are captured by the calculations (i.e., level rising at the right moment, similar periodic oscillations), as shown in Figure 5. In particular, it can be noted that the sea level shows several periodic peaks induced by the bathymetry in front of the Chilean coast that causes wave reflection (sloshing) with increasing wave heights. In Juan Fernandez the arrival time and the period are predicted correctly while the amplitude is slightly overestimated. The quality of the calculations cannot be improved considerably in this type of on-the-fly calculations with a uniform source, as shown in the next paragraphs focused on the comparison with the survey data. A comprehensive validation of the model outputs was carried out exploiting also a very detailed survey conducted along the coast by a post-tsunami survey team composed of local researchers and deployed from 17 September to 14 November 2015 [4]. The survey covered approximately 80 sites (both coastal towns with evident damage and isolated sites where the tsunami signature remained almost intact) along 500 km of the primary impact zone, from the northernmost site where damage was reported, Bahia Carrizalillo (29.11\({}^{\circ}\) S, 71.46\({}^{\circ}\) W), southward to El Yali National Reserve (33.75\({}^{\circ}\) S, 71.73\({}^{\circ}\) W) beyond which no tsunami damage was reported. The detailed analysis shows that the initial estimates of the major damage in the coastal range were correct, even if the computed range with heights exceeding 1 m (latitude in the range from 35.88  
Figure 4: Estimated maximum height at the coastline (rectangles) and tidal gauges (green triangles) used for validation (**a**). Detail of the most affected areas (**b**).