Is It Possible to Predict Strong Earthquakes?

The possibility of earthquake prediction is one of the key open questions in modern geophysics. We propose an approach based on the analysis of common short-term candidate precursors (2 weeks to 3 months prior to strong earthquake) with the subsequent processing of brain activity signals generated in specific types of rats (kept in laboratory settings) who reportedly sense an impending earthquake few days prior to the event. We illustrate the identification of short-term precursors using the groundwater sodium-ion concentration data in the time frame from 2010 to 2014 (a major earthquake occurred on February 28, 2013), recorded at two different sites in the south-eastern part of the Kamchatka peninsula, Russia. The candidate precursors are observed as synchronized peaks in the nonstationarity factors, introduced within the flicker-noise spectroscopy framework for signal processing, for the high-frequency component of both time series. These peaks correspond to the local reorganizations of the underlying geophysical system that are believed to precede strong earthquakes. The rodent brain activity signals are selected as potential "immediate" (up to 2 weeks) deterministic precursors due to the recent scientific reports confirming that rodents sense imminent earthquakes and the population-genetic model of Kirshvink (2000) showing how a reliable genetic seismic escape response system may have developed over the period of several hundred million years in certain animals. The use of brain activity signals, such as electroencephalograms, in contrast to conventional abnormal animal behavior observations, enables one to apply the standard "input-sensor-response" approach to determine what input signals trigger specific seismic escape brain activity responsesComment: 28 pages, 3 figures; accepted by Pure and Applied Geophysics. arXiv admin note: text overlap with arXiv:1202.0096, arXiv:1101.147

Assessing impacts to groundwater from CO2-flooding of SACROC and Claytonville oil fields in West Texas

Comparison of groundwater above two Permian Basin oil fields (SACROC Unit and Claytonville Field) near Snyder, Texas should allow us to assess potential impacts of 30 years of CO2-injection. CO2-flooding for enhanced oil recovery (EOR) has been active at SACROC in Scurry County since 1972. Approximately 13.5 million tons per year (MtCO2/yr) are injected with withdrawal/recycling amounting to ~7MtCO2/yr. It is estimated that the site has accumulated more than 55MtCO2; however, no rigorous investigation of overlying groundwater has demonstrated that CO2 is trapped in the subsurface. Mineralogy of reservoir rocks at the Claytonville field in southwestern Fisher County is similar to SACROC. CO2-EOR is scheduled to begin at Claytonville Field in Fisher County in early 2007. Here we have the opportunity to characterize groundwater prior to CO2-injection and establish baseline conditions at Claytonville. Methods of this study will include: (1) examination of existing analyses of saline to fresh water samples collected within an eight-county area encompassing SACROC and Claytonville, (2) additional groundwater sampling for analysis of general chemistry plus field-measured pH, alkalinity, and temperature, stable isotopic ratios of hydrogen (D/H), oxygen (18O/16O), and carbon (13C/12C), and (3) geochemical equilibrium and flowpath modeling. Existing groundwater data are available from previous BEG studies, Texas Water Development Board, Kinder Morgan CO2 Company, and the U. S. Geological Survey. By examining these data we will identify regional groundwater variability and focus additional sampling efforts. The objective of this study is to look for potential impacts to shallow groundwater from deep CO2-injection. In the absence of conduit flow from depth, we don’t expect to see impacts to shallow groundwater, but methodology to demonstrate this to regulators needs to be established. This work is a subset of the Southwest Regional Partnership on Carbon Sequestration Phase 2studies funded by the Department of Energy (DOE) in cooperation with industry and government partners.Bureau of Economic Geolog

Distribution and interaction between selected pharmaceuticals and hydrogeochemistry in Guadalhorce aquifer(South of Spain)

Management of water resources implies the study of their quality and in recent times one of the main drawbacks is the presence of non-regulated products, the so-called "Emerging Contaminants (EC)". Currently the study of these contaminants is among the research priorities of the main organizations dedicated to the protection of public and environmental, such as OMS, EPA or the EU Commission health. The list of emerging contaminants include a wide variety of products both industrial and domestic applications, whose harmful effects include toxicity, bioaccumulation, and even endocrine disruption. Conventional wastewater treatment technologies are not efficient at removing many of these contaminants, so effluents and reuse become one of the most significant sources of contamination, even many emerging pollutants are only partially degraded and are even more toxic byproducts than the parent compounds. This research is focused in the Guadalhorce porous aquifer (Malaga, south of Spain), to study the distribution of EC and the interaction with the hydrogeochemistry. 14 EC (Ibuprofen, Hydrochlorothiazide, Salicilic Acid, Triclosan, Menfenamic Acid, Carbamazepine, Trimethoprim, Ofloxacin, Cafeine, Metotrexato, Metronidazole, Sulfadiazine, Sulfamethazine and Sulfamethoxazole) and 36 paramaters including electrical conductivity, T, pH, DO, major ions (Cl-, SO42-, HCO3-, NO3-, Ca2+, Mg2+, Na+, K+), metals (B, Al, Fe, Mn, Cd, Pb, Zn, As and Se) and isotopes (d2H-H2O, d18O-H2O, d34S-SO42-) were controlled in a single field sampling (June 2012). Relationships between certain pollutants by its focus of origin are studied. Ibuprofen and Menfenamic acid follow the same pattern since they have the same use as anti-inflammatory agents and origin, mainly related to urban centers, which is important in the Guadalhorce area close to the mouth. Some possible explanations are the close situation of the Waste Water Treatment Plant of Malaga, numerous discharges of wastewater, irrigations with reused and non-reused water, among others. Nearby to the upper part of the aquifer, where farms and livestock are concentrated, pharmaceuticals for veterinary use are frequent. Furthermore, a relationship between certain emerging contaminants and hydrogeochemical characteristics present in the groundwater masses is observed, noting that ibuprofen, for example, has an indirect correlation to the temperature and concentration of certain ions such as chlorine and lead present in water masses. So it may be said that the distribution and concentration of emerging contaminants is not only affected by the number of pollution sources but also by the hydrogeochemical characteristics of the aquifer.Universidad de Málaga. Campus de Excelencia Internacional Andalucía Tech

Uranium exploration methodology in cold climates

The uranium prospecting boom of the past decade had, as a major consequence, the rapid development and proliferation of exploration methods for source materials. Numerous established methods were developed and refined whilst new techniques were introduced proving, in some instances, to be highly successful. To the explorationist the proliferation of instrumental hardware and detection systems was something of a headache with the result that in uranium exploration, more so than in other types of prospecting, the choice of exploration method at the appropriate stage of prospecting was frequently ill founded. The situation also spawned ‘black box’ purveyors who made extravagant claims for their equipment. Money was wasted through over kill applications of exploration method accompanied in many instances by deficiencies in the interpretation of results. This project was originally conceived as a means of evaluating, reviewing and filtering from a burgeoning array of systems the most appropriate exploration techniques applicable to cold climate environments. This goal has been trimmed somewhat since it had been hoped to incorporate site investigation data assembled in the field by the writer as appropriate case history material. This was not possible and as a consequence this report is a 'state of the art review' of the applicability of currently available techniques in Arctic and Subarctic environments. Reference is made to published case history data, where appropriate, supportive of the techniques or methods reviewed.Abstract -- Introduction -- Prospecting methods in relation to Arctic and Subarctic environments -- Review of direct exploration methods -- Radiometric methods -- Airborne spectrometry -- Car borne and hand held instrumentation -- Geochemical methods -- Soil and stream sediment methods -- Geobotanical methods -- Water sampling - Hydrogeochemical methods -- Other metods -- Optimal exploration method selection -- References -- Table of exploration methods discussed in this report

Diurnal and semidiurnal cyclicity of Radon (222Rn) in groundwater, Giardino Spring, Central Apennines, Italy

Understanding natural variations of Rn (222Rn) concentrations is the fundamental prerequisite of using this radioactive gas as a tracer, or even precursor, of natural processes, including earthquakes. In this work, Rn concentrations in groundwater were continuously measured over a seven-month period, during 2017, in the Giardino Spring, Italy, together with groundwater levels in a nearby well installed into a fractured regional aquifer. Data were processed to reduce noise, and then analyzed to produce the Fourier spectra of Rn concentrations and groundwater levels. These spectra were compared with the spectrum of tidal forces. Results showed that diurnal and semidiurnal cycles of Rn concentrations, and filtered oscillations of groundwater levels, in the nearby well, are correlated with solar and luni-solar components of tidal forces, and suggested no correlation with the principal lunar components. Therefore, influencing factors linked to solar cycles, such as daily oscillations of temperature and atmospheric pressure, and related rock deformations, may have played a role in Rn concentrations and groundwater levels. An open question remains regarding the correlation, which is documented elsewhere, of Rn concentrations and groundwater levels with the lunar components of the solid Earth tides

Isotopes in hydrology and hydrogeology

The structure, status, and processes of the groundwater system, which can only be acquired through scientific research efforts, are critical aspects of water resource management. Isotope hydrology and hydrogeology is a genuinely interdisciplinary science. It developed from the application of methods evolved in physics (analytical techniques) to problems of Earth and the environmental sciences since around the 1950s. In this regard, starting from hydrogeochemical data, stable and radioactive isotope data provide essential tools in support of water resource management. The inventory of stable isotopes, which has significant implications for water resources management, has grown in recent years. Methodologies based on the use of isotopes in a full spectrum of hydrological problems encountered in water resource assessment, development, and management activities are already scientifically established and are an integral part of many water resource investigations and environmental studies. The driving force behind this Special Issue was the need to point the hydrological and water resource management societies in the direction of up-to-date research and best practices

Hydrogeochemical changes before and during the 2016 Amatrice-Norcia seismic sequence (central Italy)

Seismic precursors are an as yet unattained frontier in earthquake studies. With the aim of making a step towards this frontier, we present a hydrogeochemical dataset associated with the 2016 Amatrice- Norcia seismic sequence (central Apennines, Italy), developed from August 24th, with an Mw 6.0 event, and culminating on October 30th, with an Mw 6.5 mainshock. The seismic sequence occurred during a seasonal depletion of hydrostructures, and the four strongest earthquakes (Mw ≥ 5.5) generated an abrupt uplift of the water level, recorded up to 100 km away from the mainshock area. Monitoring a set of selected springs in the central Apennines, a few hydrogeochemical anomalies were observed months before the onset of the seismic swarm, including a variation of pH values and an increase of As, V, and Fe concentrations. Cr concentrations increased immediately after the onset of the seismic sequence. On November 2016, these elements recovered to their usual low concentrations. We interpret these geochemical anomalies as reliable seismic precursors for a dilational tectonic setting

Preliminary validation of an indirect method for discharge evaluation of Pertuso Spring (Central Italy)

This paper deals with the results of the first year of the Environmental Monitoring Plan, related to the catchment project of Pertuso Spring, which is going to be exploited to supply an important water network in the South part of Roma district. The study area is located in the Upper Valley of the Aniene River (Latium, Central Italy), in the outcrop of Triassic-Cenozoic carbonate rocks, and belong to an important karst aquifer. Pertuso Spring is the main outlet of this karst aquifer and is the one of the most important water resource in the southeast part of Latium Region, used for drinking, agriculture and hydroelectric supplies. Karst aquifer feeding Pertuso Spring is an open hydrogeological system aquifer characterized by complex interactions and exchanges between groundwater and surface water which influence the aquifer water budget. Thus, evaluation of groundwater discharge from this karst spring can be affected by difficulties in performing measurements because of the insufficient knowledge about water transfer processes in the hydrological cycle and geometry of drainage conduits. The aim of this paper is to assess the interactions between karst aquifer feeding Pertuso Spring and Aniene River based on stream discharge measurements and water geochemical tracer data in order to validate an indirect method for karst spring discharge evaluation. As a matter of fact, in this paper, there are presented the results of the application of Magnesium as a reliable tracer of karst spring discharge. This indirect method is based on the elaboration of surface water discharge measurements in relationship with Mg2+ concentration values, determined as for groundwater, coming from Pertuso Spring, as for surface water sample, collected upstream and downstream of Pertuso Spring, along Aniene River streamflow. The application of Magnesium as an environmental tracer provides a means to evaluate discharge of Pertuso Spring, as it came up to be a marker of the mixing of surface water and groundwater. On the other hand, the Magnesium ion concentration provides information for the identification of groundwater flow systems and the main hydrogeochemical processes affecting the composition of water within the karst aquifers

Groundwater overexploitation and seawater intrusion in coastal areas of arid and semi-arid regions

The exploitation of groundwater resources is of high importance and has become very crucial in the last decades, especially in coastal areas of arid and semi-arid regions. The coastal aquifers in these regions are particularly at risk due to intrusion of salty marine water. One example is the case of Tripoli city at the Mediterranean coast of Jifarah Plain, North West Libya. Libya has experienced progressive seawater intrusion in the coastal aquifers since the 1930s because of its ever increasing water demand from underground water resources. Tripoli city is a typical area where the contamination of the aquifer in the form of saltwater intrusion is very developed. Sixty-four groundwater samples were collected from the study area and analyzed for certain parameters that indicate salinization and pollution of the aquifer. The results demonstrate high values of the parameters Electrical Conductivity, Na+, K+, Mg2+, Cl- and SO42-, which can be attributed to seawater intrusion, where Cl is the major pollutant of the aquifer. The water types according to the Stuyfzand groundwater classification are mostly CaCl, NaCl and Ca/MgMix. These water types indicate that groundwater chemistry is changed by cation exchange reactions during the mixing process between freshwater and seawater. The intensive extraction of groundwater from the aquifer reduces freshwater outflow to the sea, creates drawdown cones and lowering of the water table to as much as 25 m below mean sea level. Irrigation with nitrogen fertilizers and domestic sewage and movement of contaminants in areas of high hydraulic gradients within the drawdown cones probably are responsible for the high NO3- concentration in the region