# Toward a New Paradigm for Boulder Dislodgement during Storms

## TL;DR

This paper introduces a new approach to differentiate boulder dislodgement caused by storms versus tsunamis, using a coupled model to analyze how slope and wave energy influence boulder movement.

## Contribution

It presents a novel parameter study combining the TRIADS model with a Newton's Law-based boulder dislodgement model to better understand coastal boulder transport during storms.

## Key findings

- Smaller slopes increase wave energy transformation into infragravity waves.
- Larger boulders are more frequently dislodged on gentler slopes.
- Nonlinear wave processes significantly influence boulder movement.

## Abstract

Boulders are an important coastal hazard event deposit because they can only be moved by tsunamis and storms. However, storms and tsunami are competing processes for coastal change along many shorelines. Therefore, distinguishing the boulders that were moved during a storm from those moved by a tsunami is important. In this contribution, we present the results of a parameter study based on the TRIADS model coupled with a boulder dislodgement model that is based on Newton's Second Law of Motion. The results show how smaller slopes expose the waves longer to the nonlinear processes that cause the transformation of energy into the infragravity wave band causing largerboulders to be dislodged more often than on steeper slopes.