1
|
Postberg F, Sekine Y, Klenner F, Glein CR, Zou Z, Abel B, Furuya K, Hillier JK, Khawaja N, Kempf S, Noelle L, Saito T, Schmidt J, Shibuya T, Srama R, Tan S. Detection of phosphates originating from Enceladus's ocean. Nature 2023; 618:489-493. [PMID: 37316718 PMCID: PMC10266972 DOI: 10.1038/s41586-023-05987-9] [Citation(s) in RCA: 5] [Impact Index Per Article: 5.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/26/2022] [Accepted: 03/21/2023] [Indexed: 06/16/2023]
Abstract
Saturn's moon Enceladus harbours a global1 ice-covered water ocean2,3. The Cassini spacecraft investigated the composition of the ocean by analysis of material ejected into space by the moon's cryovolcanic plume4-9. The analysis of salt-rich ice grains by Cassini's Cosmic Dust Analyzer10 enabled inference of major solutes in the ocean water (Na+, K+, Cl-, HCO3-, CO32-) and its alkaline pH3,11. Phosphorus, the least abundant of the bio-essential elements12-14, has not yet been detected in an ocean beyond Earth. Earlier geochemical modelling studies suggest that phosphate might be scarce in the ocean of Enceladus and other icy ocean worlds15,16. However, more recent modelling of mineral solubilities in Enceladus's ocean indicates that phosphate could be relatively abundant17. Here we present Cassini's Cosmic Dust Analyzer mass spectra of ice grains emitted by Enceladus that show the presence of sodium phosphates. Our observational results, together with laboratory analogue experiments, suggest that phosphorus is readily available in Enceladus's ocean in the form of orthophosphates, with phosphorus concentrations at least 100-fold higher in the moon's plume-forming ocean waters than in Earth's oceans. Furthermore, geochemical experiments and modelling demonstrate that such high phosphate abundances could be achieved in Enceladus and possibly in other icy ocean worlds beyond the primordial CO2 snowline, either at the cold seafloor or in hydrothermal environments with moderate temperatures. In both cases the main driver is probably the higher solubility of calcium phosphate minerals compared with calcium carbonate in moderately alkaline solutions rich in carbonate or bicarbonate ions.
Collapse
Affiliation(s)
- Frank Postberg
- Institut für Geologische Wissenschaften, Freie Universität Berlin, Berlin, Germany.
| | - Yasuhito Sekine
- Earth-Life Science Institute (ELSI), Tokyo Institute of Technology, Tokyo, Japan
- Institute of Nature and Environmental Technology, Kanazawa University, Ishikawa, Japan
| | - Fabian Klenner
- Institut für Geologische Wissenschaften, Freie Universität Berlin, Berlin, Germany
| | - Christopher R Glein
- Space Science Division, Space Sector, Southwest Research Institute, San Antonio, TX, USA
| | - Zenghui Zou
- Institut für Geologische Wissenschaften, Freie Universität Berlin, Berlin, Germany
| | - Bernd Abel
- Leibniz-Institute für Oberflächenmodifizierung, Leipzig, Germany
- Institute of Chemical Technology, University of Leipzig, Leipzig, Germany
| | - Kento Furuya
- Earth-Life Science Institute (ELSI), Tokyo Institute of Technology, Tokyo, Japan
| | - Jon K Hillier
- Institut für Geologische Wissenschaften, Freie Universität Berlin, Berlin, Germany
| | - Nozair Khawaja
- Institut für Geologische Wissenschaften, Freie Universität Berlin, Berlin, Germany
| | - Sascha Kempf
- Laboratory for Atmospheric and Space Physics (LASP), University of Colorado, Boulder, CO, USA
| | - Lenz Noelle
- Institut für Geologische Wissenschaften, Freie Universität Berlin, Berlin, Germany
| | - Takuya Saito
- Institute for Extra-cutting-edge Science and Technology Avantgarde Research (X-star), Japan Agency for Marine-Earth Science and Technology (JAMSTEC), Kanagawa, Japan
| | - Juergen Schmidt
- Institut für Geologische Wissenschaften, Freie Universität Berlin, Berlin, Germany
- Astronomy Research Unit, University of Oulu, Oulu, Finland
| | - Takazo Shibuya
- Institute for Extra-cutting-edge Science and Technology Avantgarde Research (X-star), Japan Agency for Marine-Earth Science and Technology (JAMSTEC), Kanagawa, Japan
| | - Ralf Srama
- Institut für Raumfahrtsysteme, Universität Stuttgart, Stuttgart, Germany
| | - Shuya Tan
- Earth-Life Science Institute (ELSI), Tokyo Institute of Technology, Tokyo, Japan
| |
Collapse
|
2
|
Naik R, Sharma LK. Monitoring migratory birds of India's largest shallow saline Ramsar site (Sambhar Lake) using geospatial data for wetland restoration. WETLANDS ECOLOGY AND MANAGEMENT 2022; 30:477-496. [PMID: 35368405 PMCID: PMC8960692 DOI: 10.1007/s11273-022-09875-3] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Figures] [Subscribe] [Scholar Register] [Received: 10/26/2021] [Accepted: 03/10/2022] [Indexed: 06/14/2023]
Abstract
UNLABELLED Globally, saline lakes occupy about 23% by area, and 44% by volume. Importantly, these lakes might desiccate by 2025 due to agricultural diversion, illegal encroachment, or modify due to pollution, and invasive species. India's largest saline lake, Sambhar is currently shrinking at a phenomenal rate of 4.23% every decade due to illegal saltpan encroachments. This study aims to identify the trend of migratory birds and monthly wetland status. Birds' survey was conducted for 2019, 2020 and 2021, and combined it with literature data of 1994, 2003, and 2013, for understanding their visiting trends, feeding habits, migratory and resident birds ratio, along with ecological diversity index analysis. Normalized Difference Water Index (NDWI) was scripted in Google Earth Engine. Results state that lake has been suitable for 97 species. Highest NDWI values was 0.71 in 2021 and lowest 0.008 in 2019. Notably, the decreasing trend of migratory birds coupled with decreasing water level indicates the dubious status for its existence. If these causal factors are not checked, it might completely desiccate. Authors recommend a few steps that might help conservation. Least, the cost of restoration might exceed the revenue generation. SUPPLEMENTARY INFORMATION The online version contains supplementary material available at 10.1007/s11273-022-09875-3.
Collapse
Affiliation(s)
- Rajashree Naik
- Department of Environmental Science, School of Earth Sciences, Central University of Rajasthan, Bandarsindri, Ajmer, Rajasthan 305817 India
| | - Laxmi Kant Sharma
- Department of Environmental Science, School of Earth Sciences, Central University of Rajasthan, Bandarsindri, Ajmer, Rajasthan 305817 India
| |
Collapse
|
3
|
Characteristics of Lake Sediment from Southwestern Mongolia and Comparison with Meteorological Data. GEOSCIENCES 2021. [DOI: 10.3390/geosciences12010007] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [Abstract] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 11/16/2022]
Abstract
To understand how the climate system works in the continental interior, sediment cores that are approximately 30-cm long were taken from Olgoy, Boontsagaan, and Orog lakes, Mongolia. These cores were analyzed and compared with meteorological data (air temperature, precipitation, and wind) from climate stations in the study area. Comparison of metrological data from four stations shows similar climate fluctuations. When the temperature was high, less precipitation occurred in general. The sedimentary features measured in this study were water content, organic matter, carbonate, amorphous silica contents, whole and mineral grain size, and grain density. Excess 210Pb measurements were used to estimate sedimentary ages. According to principal component analysis (PCA), temperature correlates well to sediment characteristics in Olgoy Lake. Whole and mineral grain sizes are coarser when the temperature is high, while the amorphous-silica concentration is lower. A coarse grain size is interpreted to reflect low lake levels due to evaporation under high temperature with less precipitation. Amorphous silica may be from surrounding plants and reflects less vegetation when the temperature is high. However, in the recent 30 years, after the social system changed and overgrazing became a problem, the amount of amorphous silica has positively correlated with temperature on a short time scale. In the past 30 years, with less vegetation, amorphous silica has mainly come from weathered mineral particles. High temperature caused a thick, weathered mantle for each mineral particle, resulting in high amorphous-silica concentration. In Boontsagaan Lake, whole and mineral grain sizes are coarser when the wind speed is increased. Low precipitation correlates with a decrease in organic matter and an increase in carbonate and amorphous silica. In Orog Lake, it is difficult to establish an age model due to dried-up events. Some fluctuations in sedimentary characteristics may correspond to extreme events, such as earthquakes, and natural hazards, such as dzuds (harsh winters).
Collapse
|
4
|
Hydrogeochemical Study on Closed-Basin Lakes in Cold and Semi-Arid Climates of the Valley of the Gobi Lakes, Mongolia: Implications for Hydrology and Water Chemistry of Paleolakes on Mars. MINERALS 2020. [DOI: 10.3390/min10090792] [Citation(s) in RCA: 7] [Impact Index Per Article: 1.8] [Reference Citation Analysis] [Abstract] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 12/23/2022]
Abstract
Previous studies suggested that, generally, the climate of early Mars would have been semi-arid when the surface temperatures were above freezing. On early Mars, closed-basin lakes would have been created; however, the hydrogeochemical cycles of the lake systems are poorly constrained. Here we report results of our field surveys to terrestrial analogs of closed-basin lake systems that developed in cold and semi-arid climates: The Valley of the Gobi Lakes of Mongolia. Our results show that groundwater plays a central role not only in hydrology, but also in geochemical cycles in the lake systems. We find that groundwater predominantly flows into the lakes through local seepage and regional flows in semi-arid climates. Through the interactions with calcite-containing soils, local groundwater seepage provides Ca2+ and HCO3− to the lakes. In the wetland located in between the lakes, high-salinity shallow pools would provide Cl− and Na+ to the groundwater through infiltration. If similar processes occurred on early Mars, local seepage of groundwater would have provided magnesium and alkalinity to the early Jezero lakes, possibly leading to authigenic precipitation of lacustrine carbonates. On early Mars, infiltration of surface brine may have transported salts and oxidants on the surface to lakes via regional groundwater flows. We suggest that inflows of multiple types of groundwater in semi-arid climates could have caused redox disequilibria in closed-basin lakes on early Mars.
Collapse
|