As we continue our coverage of developments on the SMART Cable initiative, we want to make note that the center of this effort has moved to Portugal. 

It is here that the first SMART cable system is likely to be built, with the Continent-Azores-Madeira (CAM) ring project, a domestic system that could enter service as early as 2024.  The project has strong support from the Portuguese government and scientific community. 

In addition to a variety of environmental sensing capabilities, SMART technology also can be used to deliver warnings in the event of earthquakes and tsunamis, an ability that is of great interest to Portugal, which is in large part due to the country’s past experiences with devastating natural disasters.  The Great Lisbon Earthquake of 1755 and its subsequent tsunami virtually destroyed the city and is believed to have killed as many as 50,000 people. 

This brings us to a new scientific paper authored by Vitor Silva, Amir Taherian and Carlos Sousa Oliveira and published in the Bulletin of Earthquake Engineering

The paper notes that in the last five centuries, Portugal was affected by several earthquakes of greater than Magnitude 7, which have caused widespread destruction and a significant death toll. Due to the geographical distribution of moderate-to-strong magnitude events along the Tagus Valley and the Southwestern parts of the country, an earthquake early warning system might potentially provide precious warning time ahead of the arrival of the destructive seismic waves.

The abstract for the study states that the authors used “a probabilistic seismic hazard model to generate a large stochastic event set for the country, and evaluated the probability of triggering correct and false alerts considering different ground shaking thresholds. [They] propagated the aleatory variability related to the estimation of the location and event magnitude, as well as the variability in the ground shaking across the Portuguese territory.”

For the events for which a correct alert would be expected, the authors estimated the warning time for each district, considering various sources of latency. These analyses were performed considering the current seismic network of the country, as well as the potential installation of submarine sensors as part of the forthcoming renewal of the communication cables between mainland Portugal and the archipelagos of Azores and Madeira (the SMART-equipped CAM Ring cable). The results indicate that for the districts located in the Southwest of the country, an earthquake early warning system might provide sufficient warning time for risk mitigation measures to be followed.

This study only addresses earthquake, and not tsunami, warning.  Tsunami Early Warnings (TEWS), which are also possible to obtain with the future CAM Ring, are known to have a lead time considerably longer than the Earthquake Early Warning Systems (EEWS) – from tens of seconds for the EEWs to tens of minutes for the TEWs.

Vitor Silva also gave a presentation at a virtual event hosted by Portugal’s telecom regulator, Anacom, earlier this year entitled, SMART Cables in a Sea of Connectivity, Serving Science and Populations.  The slides from this presentation can be accessed here.

Thanks to Jose Barros of Anacom for information regarding the publishing of this study.