The February 6, 2023 seismic sequence that hit, the Antakya district of Hatay (T & uuml;rkiye), killed more than 50,000 people and caused extensive structural damages, resulting in the collapse of 80% of the building stock that generated over 100 million tons of debris. Understanding the impact of seismic events on water resources is highly important for ensuring human and environmental health. Herewith, a study was carried out over the Hatay area to assess the post-earthquake sustainable usability of groundwater for drinking, domestic, and irrigation purposes. 17 water points were investigated in September 2023, encompassing alluvial deposits with relatively high hydraulic conductivity as well as Miocene and Upper Cretaceous aged karstic limestone aquifers. Notably, six out of the 17 water points were crucial sources for supplying post-seismic drinking water to Hatay City. The study aimed to evaluate major ion chemistry, heavy metals, endocrine disruptors, Polycyclic Aromatic Hydrocarbons (PAHs), Polychlorinated Biphenyls (PCBs), Volatile Organic Compounds (VOCs), and other possible pollutants that potentially infiltrated into the groundwaters after seismic events. Preliminary results indicated that none of the samples exceeds the allowable limits for endocrine disruptors, PAHs, PCBs, or VOCs, posing immediate threats. However, some of the wells and springs exploited for drinking purposes show concentrations higher than the international drinking water quality standards in terms of heavy metals, particularly iron and aluminum. These findings highlight the necessity for continuous water quality monitoring and the implementation of appropriate measures to ensure the sustainable use of groundwater for drinking purposes after any earthquake. This study emphasizes the critical importance of proactive management strategies to mitigate the impact of seismic events on groundwater quality and human-environmental health in earthquake-prone regions like Hatay, T & uuml;rkiye.

A large quantity of CO2 produced in the Earth's interior is emitted to the atmosphere via soil diffusion, especially in active tectonic areas. Due to the lack of extensive in situ measurements, however, estimations of soil CO2 output have been poorly constrained thus far, leading to the perception that soil CO2 seems to be a marginal source of global carbon emissions. Here, the contribution of soil CO2 to the atmosphere is discussed based on soil degassing rates measured at 187 sites in the Tangshan seismic area, North China. The measured degassing rates ranged from 9.04 g m- 2d- 1 to 230.42 g & sdot;m- 2d- 1, with an average of 87.46 g & sdot;m- 2d- 1, suggesting that high degassing rates are common throughout the region. Carbon isotopic results show that the soil CO2 comes mainly from the deep-seated carbonates and shallow biogenetic processes. Using the threshold value of the data population (96.20 g & sdot;m- 2d- 1), the background and anomalous areas are distinguished. We find that anomalous degassing areas overlap well with epicenters of earthquakes with magnitudes greater than 5. The total annual CO2 output in anomalous areas was estimated to be 38 Mt. This extremely high value can be attributed to the enlarged degassing areas and enhanced CO2 emissions induced by regional active faults and frequent seismic activities. Our results indicate that the impact of soil CO2 emissions in seismic regions should receive increased attention.

Geochemical investigations carried out on thermal waters over the Erzin-Hatay area allowed the collection of a suite of 9 samples from natural springs and one well characterized by outlet temperatures in the range from 19.6 to 31.5 °C. All of the springs have slightly acidic pH (in the range of 6) but one sample was marked by a pH value >11 as a consequence of serpentinization processes. The water chemistry denotes water/rock interactions with either magmatic or carbonatic rocks in a water reservoir equilibrated at temperatures estimated to be in the range of 58-162 °C. The stable isotope composition of the collected waters, in terms of dD and d18O, denotes a recharge from local meteoric waters. The dissolved gases denote the contribution of no atmospheric components. CO2 is the dominant dissolved component for most of the sample, while methane is the major component for the thermal water involved in serpentinization. Besides the main components CO2 and CH4 , the dissolved gases show significant concentrations of He, H2, and CO. The isotopic composition of helium shows 3 He/4 He ratios well above that of Air Saturated Waters (ASW = 1.39 × 10-6) clearly indicating a significant contribution of 3 He of mantle origin. Taking into account the location of some sampling sites nearby the Düziçiİskenderun Active Fault Zone and the associated mantle helium contribution, we propose that fluids/faults relationships have to be considered as responsible for the feeding of deep-originated fluids to the shallow groundwater. As mantle-derived fluids are also carriers of thermal energy, the collected results strongly suggest improving the knowledge of the study area, where hydrological and geochemical considerations coupled with the tectonic setting of the area should focus on the geothermal potential of the circulating waters.

We investigate the temporal variations in stable carbon and oxygen and radiogenic Sr isotope as well as rare earth element contents of Akkaya travertine deposits in the Eskipazar region, northwest Turkey. U-Th age data indicate that studied travertines in the periphery of the 1944-earthquake rupture of the North Anatolian Fault Zone formed in a time span of 93 to 1.8 ka BP. The younger group is represented by fissure-filling carbonates whereas the older sequence is composed of veins with varying crystallization ages that are injected to bedded travertines. The age data on vein injections and fissure-ridge travertines in the Akkaya site indicate the seismic reactivation along the west-central part of the North Anatolian Fault Zone to be intensified at least 4 periods (1.8, 20, 47 and 88 ka BP) during the last 90 ka. delta O-18 and delta C-13 systematics of Akkaya travertines, which are precipitated by CO2-rich fluids depressurized during episodic seismic unrest, are in the range from -15.86 to -7.67% (VPDB) and 4.66-8.68% (VPDB), respectively. delta O-18 of the fluid equilibrating with the studied travertines is estimated in the range of -11.2 to -10.2% which is quite consistent with the average value (-12.3%) reported for the Akkaya thermal spring. Stable isotope values of travertines indicate modification by rapid CO2 degassing associated with seismic events. Helium isotope compositions of gas phase and dissolved gas of thermal fluids in the area refer to mantle contribution up to 12 %. Sr isotope values of Akkaya travertines are probably originated from Upper Cretaceous marine limestones or mafic basement rocks. REY contents are about 3 orders of magnitude lower than those of basement lithologies.

Widespread travertine deposits occur in the southwestern Great Artesian Basin (GAB) in central Australia. Priestley et al. (2018) reported uranium-series ages of travertine deposits and concluded that elevated travertine deposition rates are synchronous with wet periods and that times of travertine deposition represent times of high regional rainfall. We propose an alternative explanation that CO2 degassing from the mantle associated with active faulting played a major role in travertine precipitation in the southwestern GAB.

The understanding of the relationship between the geochemistry of fluids circulating during travertine deposition and the presence of active faults is crucial for evaluating the seismogenetic potential of an area. Here we investigate travertines from Pamukkale and Resadiye (Turkey), sited in seismic regions and next to thermal springs. These travertines formed similar to 24,500-50,000 (Pamukkale) and similar to 240-14,600 years (Resadiye) BP. We characterize fluid inclusions (FIs) and studied concentration of H2O, CO2, O-2 + N-2, and He-3, He-4, Ne-20, and Ar-40, and bulk composition (trace elements and delta C-13-delta O-18). FIs from both localities are mainly primary with low salinity and homogenization temperature around 136-140 degrees C. H2O is the major component followed by CO2, with the highest gas content measured in Pamukkale travertines. Concentrations of Ne-Ar together with O-2 + N-2 indicate that travertines from both areas precipitated from atmosphere-derived fluids. The He-3/He-4 is 0.5-1.3 Ra in Pamukkale and 0.9-4.4 Ra in Resadiye. Samples with R/Ra > 1 are modified by cosmogenic He-3 addition during exposure to cosmic rays. Excluding these data, FIs of Resadiye are mostly atmosphere-derived. This implies a shallow formation where the circulation was dominated by meteoric waters, which is consistent with their young age. Instead, FIs of Pamukkale show mixing of mantle-, crustal-, and atmosphere-derived He, indicating that these travertines formed in lithospheric fractures. Based on the delta C-13(CO2) and delta O-18 of bulk rocks, we infer that travertines formed involving crustal- (mechanochemical rather than organic) and mantle-derived CO2. Trace elements of Pamukkale and Resadiye show comparable rare earth element patterns. We conclude that travertines formed in response of seismogenetic activity.

Using a portable gas analyzer system, the geogenic gas regime below and around an ancient gate to hell at Hierapolis/Phrygia was characterized. The site was first described by Strabo and Plinius as a gate to the underworld. During centuries, it attracted even ancient tourists. In a grotto below the temple of Pluto, CO2 was found to be at deadly concentrations of up to 91%. Astonishingly, these vapors are still emitted in concentrations that nowadays kill insects, birds, and mammals. The concentrations of CO2 escaping from the mouth of the grotto to the outside atmosphere are still in the range of 4–53% CO2 depending on the height above ground level. They reach concentrations during the night that would easily kill even a human being within a minute. These emissions are thought to reflect the Hadean breath and/or the breath of the hellhound Kerberos guarding the entrance to hell. The origin of the geogenic CO2 is the still active seismic structure that crosses the old town of ancient Hierapolis as part of the Babadag fracture zone. Our measurements confirm the presence of geogenic CO2 in concentrations that explain ancient stories of killed bulls, rams, and songbirds during religious ceremonies. They also strongly corroborate that at least in the case of Hierapolis, ancient writers like Strabo or Plinius described a mystic phenomenon very exactly without much exaggeration. Two thousand years ago, only supernatural forces could explain these phenomena from Hadean depths whereas nowadays, modern techniques hint to the well-known phenomenon of geogenic CO2 degassing having mantle components with relatively higher helium and radon concentrations.

Gas geochemistry is developing into a powerful tool to understand geological processes and affirm source origins of geo-fluids. Major and trace gases, including abundances and isotopes, have shown considerable application in natural gas systems. For example, progress in unconventional gases such as shale gas, tight gas, and extreme conditions in the deep oceans represent more emerging areas and application of these novel gas-related techniques. Examples where gas geochemistry continues to place key constraints on the origin and migration characteristics of natural gas, the P-T characteristics of fluids in both subaerial and deep geothermal reservoirs, and the dynamics of the accumulation cycles, to name but a few. This volume will reflect this diversity in scope and application of gas geochemistry, focusing on deeper and broader applications in unconventional domains of novel gas geochemical techniques and applications.

We investigated the geochemical features of the gases released from the Kizildag ophiolitic complex (Hatay, Turkey). Twenty-three samples both dissolved in hyperalkaline waters and free gases (bubbling gases and dry seeps) were collected. Samples were analysed for their chemical (He, H-2, O-2, N-2, CH4 and CO2) and isotopic (He, delta C-13-CH4, delta H-2-CH4, delta H-2-H-2) composition including the content and C-isotopic composition of C-2 to C-5 alkanes in free gases. Analytical results evidence H-2 production through low temperature (<80 degrees C) serpentinization processes and subsequent abiogenic CH4 production through Fischer-Tropsch-type reactions. In some sample small additions of methane either of microbial or of thermogenic origin can be hypothesized. At one of the sites (Kisecik) a clear fractionation pattern due to microbial methane oxidation leading to strongly enriched isotopic values (delta C-13 +15 parts per thousand and delta H-2-68 parts per thousand) and depletion in methane concentrations has been evidenced. At the dry gas seep of Kurtbagi methane flux measurements have been made and a preliminary output estimation of about 1000 kg per year has been obtained. (C) 2016 Elsevier Ltd. All rights reserved.

The interior of the Australian continent shows evidence for late Quaternary to Recent fault-controlled mantle 3He and CO2 degassing. A series of interconnected NW-striking sinistral faults, the Norwest fault zone (NFZ), in south-central Australia are associated with travertine mounds, the latter show a regular spacing of 50–70 km. U-series ages on 26 samples range from 354±7 to 1.19±0.02ka (2σ errors) and suggest a clustering every ∼3–4 ka since ∼26 ka. Geochemical data demonstrate a remarkable mantle-to-groundwater connection. Isotopic data indicate that the groundwater is circulating to depths >3 km and interacting with Neoproterozoic/Cambrian basement and mantle volatiles. 3He/4He isotope ratios show that the He comes in part from the mantle. This demonstrates that the NFZ cuts through the entire crust and provides pathways for mantle degassing. Scaling relationships suggest that the series of sinistral faults that make up the NFZ are interconnected at depths and have a significant strike length of 60–70 km or more. The NFZ occurs where a major compositional boundary and a significant heat flow anomaly occurs, and a major step in lithospheric thickness has been mapped. We discuss a tectonic model in which recent stress field, heat flow and lithospheric structure in central Australia reactivated a set of steeply dipping Neoproterozoic faults, which may now be growing into a crustal/lithospheric-scale structure.

The thermal fluids vented over Eskisehir province have been investigated for their origin and to estimate the geothermal potential of the area. Thermal waters as well as bubbling and dissolved gases were collected and analysed for their chemical and isotopic features. Their isotopic composition varies in the range from -11.5 to -7.7 parts per thousand for O-18, -84 and -57 parts per thousand for H-2, and 0-7.2 TU for tritium. The gases (bubbling and dissolved) are mostly N-2-dominated with a significant amount of CO2. The helium isotopic ratios are in the range of 0.2-0.66R/Rac, indicate remarkable mantle-He contribution ranging between 2 and 10% in the whole study area. Considering the estimated geothermal gradient about three times higher than the normal gradient, and the reservoir temperatures estimated to be between 50 and 100 degrees C using quartz and chalcedony geothermometers, a circulation model was built where possible mixing with shallow waters cool down the uprising geothermal fluids.

The Eskisehir province is well-known due to its industrial and agricultural activities, which are a threat for the aquatic environment. Hence, monitoring of water quality in the area is of vital importance because of an excess heavy metal contents, especially As. The Porsuk River is heavily polluted by industrial activities from Kutahya city. It discharges into the Porsuk Dam and from there it flows relatively clean to Eskisehir city center, but beyond this point it increasingly deteriorates due to the negative impact of industrial and agricultural activities up to the junction point of Porsuk and Sakarya rivers. Heavy metal concentrations and As contents in surface and ground waters were selected as pollution indicators to examine pollution level and compare an interaction between river and groundwater. For this purpose, water samples taken between 2008 and 2010 from the Porsuk River along the section from the west of Kutahya to the discharge point into the Sakarya River, as well as groundwater samples from the wells located close to or far of the Porsuk River, were evaluated. Based on the obtained results, we found that the Porsuk River, especially at the locations close to the Sakarya River, and groundwater are polluted in terms of heavy metals and As compounds. In conclusion, the heavy metal and As pollution is also observed in the wells close to the locations in which groundwater is fed by the Porsuk River since it acts as an influent river. Thus, surface water is considered as a polluting source of groundwater.

Speleothem-based stable isotope records are valuable in sub-humid and semi-arid settings where many other terrestrial climate proxies are fragmentary. The Eastern Mediterranean is one such region. Here we present an 80-kyr-long precisely-dated (by U-series) and high-resolution oxygen (δ 18 O) and carbon (δ 13 C) records from Dim Cave (~36°N) in SW Turkey. The glacial-interglacial δ 18 O variations in the Dim Cave speleothem are best explained in terms of changes in the trajectories of winter westerly air masses. These are along a northerly (European) track (isotopically less depleted) during the early last glaciation but are gradually depressed southward closer to the modern westerly track along the North African coast (more depleted) after c.50 kyr and remain in the southern track through the Last Glacial Maximum. The southward displacement of the westerly track reflects growth of the Fennoscandian ice sheet and its impact on westerly wind fields. Changes in δ 13 C are interpreted as reflecting soil organic matter composition and/or thickness. δ 13 C values are significantly more negative in interglacials reflecting active carbonic acid production in the soil and less negative in glacial times reflecting carbonate rock values. Several Heinrich events are recorded in the Dim record indicating intensification of westerly flow across this part of the EM.

In Greek mythology the netherworld is guarded by the three-headed hellhound Kerberos. For persons who have passed away, it is rather easy to find the way down to the realms of the shadows. Yet, there is no escape from the world of Hades. The gates to hell were used by the souls of the deceased but also by diseased people seeking cures or prophecies. In ancient times, these gates to the abyss were always connected to unexplainable geo-biological phenomena. These were regions of vapors, deadly gases, darkness, bubbling springs, and color changing creeks. Additionally, places where animals showed strange behavior or plant growth was irregular were selected for sanctuaries, oracles, or gates to the Hadean. Often but not always, carbon dioxide played a decisive role at these entrances, as it is colorless, tasteless, and kills all aerobic life quite quickly in higher concentrations.