| Abbreviation | Definition |
|---|---|
| HR | Horizontal Reference |
| HS | Hunsucker Spring |
| HTMP | Hyperbolic Topographic Mapping for Proximity Data |
| HUFF | High Undergrads Feeling Fine |
| HWDP | Heavy Weight Drill Pipe |
| I | Island |
| IAAC | International Antarctic Analysis Centre |
| IAVCEI | International Association of Volcanology and Chemistry of the Earth's Interior |
| IB | Injection Borehole |
| IB | Intercontinental Belt |
| IBF | Integrated Basin Flow |
| ICB | inner core boundary |
| ICEF | International Commission on Earthquake Forecasting for Civil Protection |
| ICSL | Independent Coloured Stones laboratory |
| ICSM | Intergovernmental Committee on Survey and Mapping |
| ICWG | Ice Core Working Group |
| IDC | Imputed Days of Contribution |
| IDCA | Indian Diamond and Colorstone Association |
| IFM | Indicative Flood Map |
| IGBN | Inferred Geological Boundary North |