An Oasis Exists Because Water Reaches the Surface
An oasis is a fertile spot in a desert. It forms where an aquifer comes close enough to the surface to be reached.
An oasis is a fertile area in a desert where water is available. It is not a chance puddle: an oasis forms where an underground aquifer reaches or nears the surface, often where rock layers force water upward or where the land dips below the water table. Many desert aquifers hold *fossil water* that fell as rain thousands of years ago and is not being replaced. The plural is *oases*, following the Greek pattern.
- A fertile desert spot. *A desert oasis.*
- A place of relief. *An oasis of calm.*
- Aquifer — the water source. *An underground aquifer.*
- Fossil water — ancient groundwater. *Fossil water.*
- Oases — the plural. *Several oases.*
Word forms
| Form | Word | Example |
|---|---|---|
| Noun | oasis | An oasis. |
| Plural | oases | Two oases. |
| Figurative | oasis | An oasis of calm. |
| Related | aquifer | An aquifer. |
| Greek | oasis | A fertile spot. |
- The caravan stopped at the oasis.Desert.
- The garden is an oasis of quiet.Figurative.
- Fossil water is not replenished.Hydrology.
Why oases can disappear
- Fossil water fell thousands of years ago and is not replaced
- Deep pumping for irrigation lowers the water table
- Once the table drops below root depth, palms die
- Some historic oases have already been abandoned
- Recharge rates in true deserts are effectively zero
Late Latin *oasis*, from Greek, apparently from an Egyptian or Coptic word for a fertile place in the desert.
How does an oasis get its water?
From an underground aquifer that reaches or nears the surface, sometimes forced up by rock layers or reached by wells.
What is fossil water?
Groundwater that fell as rain thousands of years ago and is not being replenished, so extracting it depletes the supply permanently.