Water Resources and Environment
(University of Southern California, NASA Jet Propulsion Laboratory)
Exploring Subsurface Volatiles Occurrence On Planetary Surfaces And Earth’s Arid Areas Using Radar Observations
Water on Mars, on Jupiter Icy Moons, on Asteroids and perhaps even more water on more bodies of our solar system — Are water and life unique to Earth? The last decade of planetary exploration suggests that the liquid water, uniquely characterizing, our blue planet is potentially a transitional phase that other bodies of our solar system may have gone through or will be transiting to during their evolution. On Earth, as well as other bodies of the solar system, the evidence of water and climatic evolutions are often found in the first few kilometers of the subsurface. Today, planetary sounding and imaging techniques have provided new insights into understanding the unseen evolution history of the Earth, Moon, Venus, Mercury, comets and Mars—as well as numerous other bodies in our solar system hunting traces of water and ice and exploring new habitable environments. The returned data reveals the similarities and discrepancies between our planets and the other bodies of the solar system. In this lecture dedicated to the general audience, Dr. Heggy will speak about how sounding methods are being used to explore evidence of possible deep subsurface aquifers and ice deposits on Mars, asteroids and comets and how these methods are being used to understand the evolution of groundwater recourses in North Africa and the Arabian Peninsula and their responses to climatic and anthropogenic stresses. The lecture will also discuss the uncertainty and the evolution of water shortage in the Middle East and its implications on the stability of the area for the upcoming few decades.
Friday, 8 July 2022, 1 p.m.
Brückstraße 3a, 39114 Magdeburg, Hybrid: Seminar Room 1 & online
Essam Heggy is a Planetary Scientist at the Viterbi School of Engineering in the University of Southern California and the NASA Jet Propulsion Laboratory. Heggy obtained both Master and PhD in Astronomy and Astrophysics with a major in Space and Planetary sciences respectively in 1999 and 2002 with distinguished honours from the Sorbonne-UPMC Paris University in France. His research interests in space and planetary geophysics aims to understand water and ice distributions in Earth arid regions, Mars, the Moon, Icy satellites and Near-Earth Objects. His research involves probing structural, hydrological and volcanic elements in terrestrial and planetary environments using different types of radar imaging and sounding techniques as well as measuring the electromagnetic properties of rocks in the radar frequency range. He is currently a member of the science team of the MARSIS instrument aboard the Mars Express Orbiter, the Mini-SAR experiment aboard Chandrayaan-1, the Mini-RF experiment on board the Lunar Reconnaissance Orbiter, the CONSERT radar experiment on board the Rosetta mission and the WISDOM Radar onboard the ESA ExoMars Rover planed for 2020. He is also a contributing scientist to several proposed planetary and terrestrial radar imaging and soundings experiments and participated in several NASA radar mission concept designs. Dr. Heggy is also an Associate Professor at the Institute de Physique du Globe de Paris, Paris, France.
Mass development of coliform bacteria in oligotrophic lakes and reservoirs:
monitoring, causes, and relevance for water supply
Monday, 18 July 2022, 3 p.m.
Brückstraße 3a, 39114 Magdeburg, Seminar Room
Surface waters are one of the main sources for drinking water production, thus microbial contamination should be as minimal as possible. In recent years, increased numbers of coliform bacteria have been observed in oligotrophic lakes and reservoirs used for drinking water production. Certain strains of coliform bacteria, namely Enterobacter asburiae and Lelliottia spp., have been shown to be present during summer months, reaching values above 104 per 100 ml, representing an increase of four orders of magnitude compared to winter. Interestingly, the same, very closely related strains have been found in several reservoirs from different regions in Germany. The fecal indicator bacteria Escherichia coli and enterococci could only be detected in low concentrations. Furthermore, fecal marker genes were not detected in the reservoir, indicating that high concentrations of coliform bacteria were not due to fecal contamination. Microbial community revealed Frankiales and Burkholderiales as dominant orders.
Nevertheless, such high concentrations challenge drinking water treatment and occasionally the respective coliform bacteria have been detected in the treated drinking water. Thus, the question of their hygienic relevance is of high importance for water suppliers and authorities. Genomic analyses suggest that the strains are not hygienically relevant, as typical virulence factors are absent and antibiotic resistance genes in the genomes most likely are of natural origin. The genome analyses further suggest adaptations to oligotrophic and changing environmental conditions, like e.g., genes to cope with low nitrate and phosphate levels and the ability to utilize substances released by algae, like amino acids, chitin, alginate, rhamnose and fucose. This leads to the hypothesis that the proliferation of the coliform bacteria could occur due to algae die-off.
We conclude that the proliferation in reservoirs and lakes during stable summer stratification is an autochtonic process of certain E. asburiae and Lelliottia strains, that are well adapted to the surrounding oligotrophic environment. It is correlated to higher water temperatures in summer and is therefore such “coliform bloom” are expected to occur more frequently in the near future, challenging drinking water production.
(GFZ in Potsdam/ Section "Climate Dynamics and Landscape Evolution")
Monday, 12 September 2022, 3 p.m.
Brückstraße 3a, 39114 Magdeburg, Seminar Room
Linda C. Weiss (Ruhr-University Bochum, Department of Animal Ecology, Evolution and Biodiversity)