While in some accounts Apollo's birth itself fixed the floating Delos to the earth, there are accounts of Apollo securing Delos to the bottom of the ocean a little while later.
wˌaɪl ɪn sˌʌm ɐkˈaʊnts ɐpˈɑːloʊz bˈɜːθ ɪtsˈɛlf fˈɪkst ðə flˈoʊɾɪŋ dᵻlˈoʊz tə ðɪ ˈɜːθ, ðɛɹˌɑːɹ ɐkˈaʊnts ʌv ɐpˈɑːloʊ sᵻkjˈʊɹɹɪŋ dᵻlˈoʊz tə ðə bˈɑːɾəm ʌvðɪ ˈoʊʃən ɐ lˈɪɾəl wˌaɪl lˈeɪɾɚ.