sˌʌm ˈɛɹiəz kʊd nˌɑːt biː sɚvˈeɪd wɪð dʒˌiːoʊfˈɪzɪks ænd sˌoʊ ɡɹˈaʊndpˈɛnɪtɹˌeɪɾɪŋ ɹˈeɪdɑːɹ wʌz jˈuːzd tə fˈɪl ɪnðə ɡˈæps.
Some areas could not be surveyed with geophysics and so ground-penetrating radar was used to fill in the gaps.