https://chs.coast.noaa.gov/htdata/Inundation/SLR/BulkDownload/DEMs/GU/Guam_GCS_3m_GUVD04m_Fy23.tif
https://chs.coast.noaa.gov/htdata/Inundation/SLR/BulkDownload/DEMs/GU/Guam_dem_metadata_fy23.xml