| from natural gas | 6 | other |
| from beneath the glacier | 5 | location |
| from a variety of suitable sources | 4 | other |
| methane → be → derived | 8 |
| methane → be → sourced | 6 |
| methane → be → obtained | 5 |
| negative | neutral | positive |
| 0.167 | 0.777 | 0.057 |
| Raw frequency | 19 |
| Normalized frequency | 0.391 |
| Modifier score | 0.900 |
| Perplexity | 235.962 |