Diatoms in tsunami deposits
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Keyword | | Author keywords | Diatom field and laboratory methods; Diatom paleoecology; Diatom taxonomy; subduction zone paleoseismology; Tsunami deposits; Tsunami geology |
Authors | | Top | - Dura, T.
- Hemphill-Haley, E.
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Abstract | Diatoms found within widespread sand beds deposited by tsunamis provide the framework for some of the most detailed historical and long-term (centuries to millennia) earthquake and tsunami reconstructions. In this chapter, we explore how the salinity preferences, life forms, and valve structures of diatoms are particularly useful for identifying tsunami sands within a variety of low-energy coastal environments around the world. We discuss the highly variable “signature” of diatoms within tsunami deposits and describe instances where clearly anomalous, allochthonous marine and brackish diatoms within tsunami deposits help support a marine incursion. We highlight how the fragmentation and sorting of diatom valves may provide evidence of high-energy transport during the rapid, turbulent flow of a tsunami; the potential use of diatoms to estimate tsunami runup beyond the landward limit of sedimentation; and the challenges in differentiating tsunami from storm deposits using diatoms. |
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