What is in a pebble shape?

TL;DR

This paper introduces a method to characterize flat pebble shapes using curvature distributions, linking shape evolution to erosion processes and providing insights beyond traditional aspect ratio measurements.

Contribution

It presents a novel approach to analyze pebble shapes through curvature distributions and compares experimental data with erosion models.

Findings

Curvature distribution complements aspect ratio in shape analysis.

Erosion is faster at protruding regions of high curvature.

The method links shape evolution to erosion dynamics.

Abstract

We propose to characterize the shapes of flat pebbles in terms of the statistical distribution of curvatures measured along the pebble contour. This is demonstrated for the erosion of clay pebbles in a controlled laboratory apparatus. Photographs at various stages of erosion are analyzed, and compared with two models. We find that the curvature distribution complements the usual measurement of aspect ratio, and connects naturally to erosion processes that are typically faster at protruding regions of high curvature.