Table 1. The physical and geochemical parameters in the BSI layer and brine bodies of five deep hypersaline anoxic brines from the Red Sea.
| Parameters | Atlantis II Deep (S-W basin)a | Discovery Deepa | Erba Deepa | Kebrit Deepa | Nereus Deep (E-W basin)a | ||||||||
|---|---|---|---|---|---|---|---|---|---|---|---|---|---|
| |
BSI |
UCL1 |
UCL2 |
LCL1 |
Brine |
BSI |
Brine |
BSI |
Brine |
BSI |
Brine |
BSI |
Brine |
| Depth (m) | 1998 | 2006 | 2025 | 2048 | 2062 | 2038 | 2141 | 2381 | 2392 | 1467 | 1490 | 2432 | 2445 |
| Salinity (%) | 5.6 | 8.6 | 11.2 | 15.4 | 26.2 | 13.8 | 26.0 | 9.8 | 18.1 | 18.2 | 26.0 | 15.4 | 22.4 |
| Temp. (°C) | 31.8 | 46.0 | 52.1 | 65.0 | 67.8 | 35.8 | 44.8 | 23.1 | 28.2 | 21.9 | 23.4 | 27.9 | 30.1 |
| pH | 6.5 | 5.8 | 5.7 | 5.2 | 5.1 | 6.6 | 6.4 | 7.7 | 7.2 | 5.7 | 5.2 | 7.7 | 5.5 |
| Oxygen (μM) | 2.2 | 0.5 | 0.5 | 0.5 | 0.3 | 0.3 | 0.3 | 0.3 | 0.3 | 4.6 | 2.3 | 0.3 | 2.8 |
| Nitrate (μM)b | 55.3 | 37.9 | 46.1 | 21.9 | 32.7 | 30.1 | 43.9 | 29.0 | 55.5 | 28.4 | 44.1 | 24.2 | 59.1 |
| Ammonia (μM) | 2.0 | 107.0 | 174.0 | 378.0 | 806.0 | 289.0 | 852.0 | 190.0 | 691.0 | 2017.0 | 2657.0 | 650.0 | 1116.0 |
| Urea (μM) | 1.7 | 1.5 | 1.3 | 1.0 | < 0.1 | 1.3 | 1.5 | 1.4 | 1.6 | < 0.1 | 1.1 | 2.4 | < 0.1 |
| Sulfate (mM) | 32.5 | 30.2 | 28.7 | 25.2 | 8.3 | 26.7 | 8.4 | 38.6 | 41.6 | 31.1 | 27.7 | 22.5 | 10.5 |
| H2S (μM) | –c | – | – | – | – | – | – | – | – | 149.8 | 526.7 | – | – |
| Mn (mM) | 0.1 | 0.8 | 1.2 | 1.8 | 1.7 | 0.5 | 1.1 | 0.2 | 0.6 | 0.1 | 0.2 | 0.9 | 1.0 |
| Fe (μM) | 0.5 | 0.8 | 24.5 | 70.5 | 1528.0 | 0.6 | 0.1 | < 0.1 | 31.8 | 40.4 | 1.5 | 0.5 | 27.2 |
| Chloride (M) | 0.8 | 1.5 | 2.0 | 3.0 | 5.2 | 2.5 | 5.1 | 1.6 | 3.3 | 3.4 | 5.0 | 2.9 | 4.2 |
| Bromide (mM) | 1.0 | 1.1 | 1.2 | 1.3 | 1.5 | 1.3 | 1.5 | 1.1 | 1.4 | 2.5 | 3.0 | 2.4 | 1.5 |
| Ca (mM) | 17.3 | 38.8 | 52.3 | 81.6 | 142.2 | 64.0 | 134.1 | 21.0 | 32.7 | 49.0 | 53.6 | 140.0 | 224.7 |
| B (mM) | 0.5 | 0.6 | 0.6 | 0.7 | 1.0 | 0.7 | 1.0 | 0.6 | 0.7 | 2.1 | 2.5 | 0.8 | 0.8 |
| Li (μM) | 49.6 | 126.0 | 174.9 | 286.0 | 522.7 | 231.3 | 431.9 | 42.9 | 68.8 | 360.7 | 406.6 | 248.9 | 186.9 |
| Na (M) | 0.7 | 1.4 | 1.8 | 2.9 | 4.9 | 2.3 | 4.7 | 1.5 | 3.2 | 3.2 | 4.8 | 2.5 | 3.5 |
| K (mM) | 13.2 | 20.8 | 26.3 | 40.4 | 63.2 | 31.4 | 60.8 | 17.1 | 34.5 | 26.5 | 35.5 | 52.8 | 71.4 |
| Mg (mM) | 61.8 | 55.9 | 51.6 | 44.6 | 29.1 | 49.5 | 33.0 | 61.1 | 71.4 | 104.3 | 118.7 | 67.3 | 67.4 |
| Sr (μM) | 121.5 | 190.7 | 236.2 | 338.4 | 596.8 | 284.6 | 599.7 | 176.9 | 265.8 | 631.6 | 685.2 | 476.5 | 712.2 |
| Si (mM) | 0.1 | 0.4 | 0.5 | 0.7 | 1.0 | 0.3 | 0.1 | 0.1 | 0.2 | 0.4 | 0.6 | 0.1 | 0.1 |
| Ba (μM) | 1.7 | 6.2 | 9.7 | 1.2 | 1.9 | 1.7 | 5.6 | 5.0 | 1.2 | 0.8 | 1.0 | 0.2 | 3.7 |
Abbreviations: BSI, brine-seawater interface; LCL, lower convective layer; Temp., temperature; UCL, upper convective layer.
a
Sampling locations (Lat./Long.): Atlantis II (21° 20.76'/38° 04.68'); discovery (21° 16.98'/38°) nereus (23° 11.53'/37° 25.09'). More details in Supplementary Figure 1.
b
Nitrite was below detection limit (0.1 μM).
c
Below detection limit (∼1 μM).