| Abbreviation | Definition |
|---|---|
| IGBP | International Geosphere Biosphere Programme |
| IGC | International Geological Congress |
| IGN | Institut Geographique National |
| IGP | Interactive Geology Project |
| IGQ | Illinois Geologic Quadrangle |
| IGRM | Irish Geological Research Meeting (Ireland) |
| IGRS | Institute of Geoinformatics & Remote Sensing |
| IGS | Institute of Geological Sciences |
| IGU | International Geophysical Union |
| IHP | International Hydrological Program |
| IMGA | International Medical Geology Association |
| IMPRC | Iran Mineral Processing Research Center |
| INSAR | Interferometric Synthetic Aperture Radar |
| IOCG | Iron-Oxide Copper Gold district |
| IOCK | Iron Oxide Coated Keramzite |
| IP | Intermediate Period |
| IPIZ | Interior Pack Ice Zone |
| IPSG | Institute of Petrology and Structural Geology |
| IRBM | Integrated River Basin Management |
| IRIS | Incorporated Research Institutions for Seismology |