 Halayyar ɗumi ba tsayayye ba ce kamar manyan koguna a cikin ƙasa waɗanda galibi su ke riƙe zafin jiki na yau da kullun, amma ya yi daidai da waɗan kasancewarsu ramuka masu zurfi a cikin ƙasa, in ji Glen Cushing na kungiyar Nazarin Albarkatun Ƙasa ta Amurka USGS Ƙungiyar Nazarin Taurari da kuma na Jamiar Arewacin Arizona da ke a Flagstaff, Arizona. 