Lessons learned from the 21ST August 2018 Mt 6.9 earthquake in Trinidad

International audience On 21st August 2019 evening, Trinidad was rocked by an Mt 6.9 magnitude earthquake occurring north of the Paria Peninsula. It is the largest magnitude event of the past 250 years and resulted in minor damages on buildings at the north of the island and significant deformation on the ground at the southern part. Analysis of data from the Port of Spain Strong Motion Network reveals that the level of structural damage in the capital is between the expected ranges, while structures built without engineering inspection suffered more severe damage. At the south area of Los Iros, significant ground deformation led to the destruction of agricultural farms and ponds, while an area prone to landslide slumped to the coast. Ongoing research shows the area subjected to lateral spreading due to the prolonged duration of the earthquake. The UWI SRC collected more than 1000 citizen reports through the online “Did You Feel It?” module and the Citizen Seismologist Project, revealing the spatial distribution of perception of shaking. Macroseismic intensity map shows a normal distribution of the ground shaking decreasing with distance. A social media poll a year later shows that citizens responded to the violent shaking with prayers and fear, while a lot were concerned about their family and caught by surprise. The low level of damage created the false impression to a lot of citizens throughout the country that the building stock is of high quality, when compared to other areas with similar magnitude events (e.g. Haiti, 2010), not taking into account the geometrical parameters of the different events.