The United States Geological Survey estimates that there are  of undiscovered, technically recoverable gas from natural gas hydrates on the Alaskan North Slope.
ðə juːnˈaɪɾᵻd stˈeɪts dʒˌɪəlˈɑːdʒɪkəl sˈɜːveɪ ˈɛstᵻməts ðæt ðɛɹˌɑːɹ ʌv ʌndɪskˈʌvɚd, tˈɛknɪkli ɹᵻkˈʌvɚɹəbəl ɡˈæs fɹʌm nˈætʃɚɹəl ɡˈæs hˈaɪdɹeɪts ɔnðɪ ɐlˈæskən nˈɔːɹθ slˈoʊp.