| Abbreviation | Definition |
|---|---|
| LK | Lake |
| LKO | Lowest Known Oil |
| LLD | Deep LaterLog |
| LLD | Log Linear Detrending |
| LLD | Long-Lasting Depolarization |
| LLOF | Landslide Lake Outburst Flood |
| Lm | Meander Length of river or stream |
| LMFU | Local Maxima Finder Unit |
| LOA | Level Of Activity |
| LPB | Lake Pontchartrain Basin |
| LSM | Little Skull Mountain |
| LSRB | Lower Susquehanna River Basin |
| LTRS | Laboratory for Terrestrial Remote Sensing |
| LVST | Laboratory Vane Shear Test |
| LVZ | Low Velocity Zone |
| LWBZ | Lower Water Bearing Zone (aquifer; Florida) |
| LWD | Logging While Drilling |
| MAC | Mid-Atlantic Cape |
| MACS | Master Active Control Station |
| MAGST | Mean Annual Ground Surface Temperature |