Tsunami
There are a number of challenges in defining the tsunami risk, primarily related to uncertainties in the location, type and overall geometry of the generating mechanism. The Caribbean is a tectonically diverse environment, with many plate boundaries, some of which are transverse and others close to Barbados are subduction faults. There are also volcanic cones that could collapse and/or explode and the potential for submarine landslides. Many of the processes that are associated with volcanic activity along the lesser Antilles are far enough away and directed towards the west, such that their direct impact on Barbados would be limited.
The most probable tsunami threats in the vicinity of Barbados at the 100 year level involve a subduction earthquake, similar to those that occurred in 1839 and 1843 to the east of Martinique. These events caused some damage in the northern Lesser Antilles and only limited impacts in Barbados. There is the potential for a large subduction event directly east of Barbados, although there is no historic evidence of such events, suggesting that these events would be well beyond the 100 year event. There are so few strong historical seismic events recorded in the region that defining specific parameters for an expected 100 year event is close to impossible.
Identificación de fuentes sísmicas
Caracterización del potencial de generación de terremotos de cada fuente
Modelación de la distribución de la intensidad sísmica como una función de la magnitud y la distancia
Aplicación de la teoría de la probabilidad
- The most probable tsunami threats in the vicinity of Barbados at the 100 year level involve a subduction earthquake, similar to those that occurred in 1839 and 1843 to the east of Martinique. These events caused some damage in the northern Lesser Antilles and only limited impacts in Barbados.
- There are a number of challenges in defining the tsunami risk, primarily related to uncertainties in the location, type and overall geometry of the generating mechanism.
- Many of the processes that are associated with volcanic activity along the lesser Antilles are far enough away and directed towards the west, such that their direct impact on Barbados would be limited.
- The 100 year event in Barbados was simulated with various tsunamis similar to the 1839 and 1843 events.
Tsunami damage in Barbados is expected to be very minor for the 100 year return period that was requested for the NCRIPP, is limited to the following areas:
Brandons Beach may see tsunami runup along the beach and across the Spring Garden Highway. The simulations show some threatened regions in the vicinity of the Fishing Harbour (within the fish-market area and parking lot).
Some flooding is possible in the lower Careenage, in the immediate waterfront region, along the shore of Carlisle Bay, although with limited impact on any structures and in the vicinity of the boat yard to the west of the pier, as well as in the fish market area to the east of the pier (towards the bus depot).
With minimal assets exposed to tsunami inundation at the 100 year return period, it is not necessary to derive new flood-damage information specific to tsunamis. The manner in which damage will occur in the event of a tsunami will be very similar to that of a storm surge event A combination of waves and ponded salt water would create similar damage. If tsunamis were a much larger threat, in terms of physical height and asset exposure, a different approach may be required.
Tsunamis in Barbados at the 100 year level are expected to have minimal effects in very specific regions. However, tsunamis are very likely associated with a seismic event, which could also have an impact in Barbados. This would depend on the severity of the quake and the distance away from Barbados. For this reason, it is important to consider emergency services and transportation routes in the event that recovery operations are underway from a seismic event when the tsunami is occurring.
- If tsunamis were a much larger threat, in terms of physical height and asset exposure, a different approach may be required.
- Tsunamis are very likely associated with a seismic event, which could also have an impact in Barbados. This would depend on the severity of the quake and the distance away from Barbados.
- With the small surface area that is covered by the tsunami hazard and the presence of many multi-story buildings, loss of life would be limited. Expected numbers would be less than one for the present condition, and 1 to 3 for the future scenario.
The assets exposed to tsunami hazard Housing Stock: A minimal number of homes in the vicinity of Brandons and the south end of Brighton Beach.
Fish Market Facilities: In the region of the fishing harbour and Oistins the most threatened assets are the structures associated with the fish market. Most of these structures are open-air shelters (no walls) and would see minimal structure damage, and only minor content damage in the event of a tsunami. Boats (in- water and on-land) could be affected by a tsunami. However, moored vessels may ride out a mild tsunami (mostly) without incident. Vessels on shore are probably high enough that water from a tsunami would not move the vessels. Note that a significant number of vessels on the land are under repair, with many of them being out of service for many years.
Commercial Structures: In the vicinity of the Careenage, there are some store fronts, office buildings and warehouses that could be affected by tsunami flooding.
- Tsunamis in Barbados at the 100 year level are expected to have minimal effects in very specific regions.
- The greatest uncertainty in tsunami risk relates to the generation of the tsunami wave and the manner in which it travels towards Barbados.
- The combined occurrence of a tsunami with rough conditions on the west coast has not been considered and is outside the scope of this study.
- Tsunami damages for the present day condition are concentrated in the Bridgetown area and are almost entirely commercial damages (>99%) as opposed to residential damages.
