Kammala jumla mai zuwa: Erosion yana fitar da tarkace daga tsaunuka kuma ya sauka zuwa Tekun Atlantika (a gefen gabas) da Gulf of Mexico (a yamma). Wannan motsi na sediment na iya sauƙaƙa matsin lamba na dutsen da ke sama da kuma haifar da tsoffin kurakurai (da zarar sun kasance masu aiki a yayin ayyukan ginin dutse) don sake kunnawa da ƙirƙirar girgizar ƙasa. An yi imanin cewa wannan wani lamari ne a cikin girgizar kasa ta Sparta ta 2020 da kuma wasu a yankin kamar su
Girgizar kasa ta shekara ta 2011 a Virginia.