High-resolution analysis of a tsunami deposit: Case-study from the 1755 Lisbon tsunami in southwestern Spain

A multi-proxy approach using trench sediment analysis on the southwestern coast of Spain (Los Lances Bay, Andalusia) provides a high-resolution record of the 1755 Lisbon tsunami and offers new means to interpret tsunami deposits. A combination of sedimentological (grain size, sorting, AMS), micromorphological (X-ray tomography and radiography, thin sections) and geochemical analyses (X-ray microfluorescence, ICP-AES) combines to provide a comprehensive reconstruction of the different phases of tsunami deposition and flow dynamics. Vertical variations in sediment texture, fabric and composition of the 1755 tsunami deposits in Los Lances are then discussed with reference to existing literature on diagnostic criteria commonly used for identifying and interpreting tsunami deposits. Finally possible leads for future investigation are proposed.