Thank you for visiting nature.com. You are using a browser version with limited support for CSS. To obtain
the best experience, we recommend you use a more up to date browser (or turn off compatibility mode in
Internet Explorer). In the meantime, to ensure continued support, we are displaying the site without styles
and JavaScript.
Rayleigh-wave phase-velocity maps of the study area at the periods of 3, 4, 5, 6, 9, and 12 s. The maps are highly correlated at all periods with those published in previous studies20, 21.