Magnitude Scale Research Articles

Liquefaction potential hazard study at UIN Datokarama, Palu City, Central Sulawesi

In June 2019, the Asian Development Bank approved emergency rehabilitation and reconstruction assistance (EARR) to help Indonesia rebuild better critical infrastructure damaged by the 2018 Palu-Donggala earthquake. One of the EARR sub-projects is the reconstruction of Universitas Islam Negeri (UIN) Datokarama that suffered significant damage from the combined effects of the tsunami and earthquake. The design for the building's reconstruction incorporated better principles of deconstruction, including pile foundations to ensure the facilities are earthquake, tsunami, and liquefaction resistant. This study purpose is to evaluate liquefaction potential and estimate its severity or damage potential to structures in the reconstruction site. Liquefaction potential will be assessed in two ways, first by using soil deposits grain sizes distribution method from Japan technical standards for port and harbour facilities and second by safety factor against liquefaction (FOS) method using the SPT-based liquefaction triggering analysis with the revised magnitude scaling factor (MSF) relationship by Idriss and Boulanger. Liquefaction Potential Index (LPI) from Iwasaki will be used for estimating liquefaction severity. The analysis is performed on dataset taken from 6 boreholes in location dominated by saturated sandy soil and shallow ground water. Based on the result, liquefaction potentially triggered at various depth with consistent LPI index at > 15, The reconstruction site has a very high liquefaction risk.

Bitter taste sensitivity, cruciferous vegetable intake, obesity, and diabetes in American adults: a cross-sectional study of NHANES 2013-2014.

Objective: To examine the associations between bitter taste sensitivity, cruciferous vegetable consumption, and likelihood of obesity and diabetes among American adults. Research design and method: Cross-section observation of 2129 adults aged 40-80 years of the National Health and Nutrition Examination Survey (NHANES) 2013-2014. Bitter taste sensitivity was estimated by the generalized labeled magnitude scale (gLMS) rating for bitterness (non-tasters: the lowest 25%, the others were tasters). Consumption of cruciferous vegetables was recorded by the 2 day 24 hours dietary records. Obesity was defined as body mass index (BMI) ≥30 kg m-2. Diabetes was defined as self-reported physician-diagnosed diabetes, or who reported taking diabetes medication or individuals with a fasting plasma glucose (FPG) ≥ 126 mg dL-1 or Hemoglobin A1c ≥ 6.5%. Results: The proportion of participants who ate cruciferous vegetables over the two days was 29.5% among bitter tasters, significantly lower than that (35.7%) among non-tasters (P = 0.04) after adjustment of age, gender, race/ethnicity, dietary energy intake, physical activity, education, smoking and income levels. Among participants who ate cruciferous vegetables, bitter tasters on average consumed 15.5 g (±7.0) grams less cruciferous vegetables per day compared to non-tasters. The multi-variates adjusted odds ratio of obesity was 1.29 (95% confident interval (CI): 0.76-2.17), 1.40 (95% CI: 0.90-2.18) and 1.68 (95% CI: 1.05-2.67) among bitter tasters who ate cruciferous vegetables, among non-tasters who did not ate cruciferous vegetables, and among bitter tasters who did not eat cruciferous vegetables, respectively, as compared with non-tasters who ate cruciferous vegetables. The prevalence of diabetes was 17.3% and 13.0% among bitter tasters and non-tasters, respectively, with a multi-adjusted odds ratio of 1.32 (95% CI: 1.02-1.69, P = 0.033) for diabetes comparing bitter tasters with non-tasters, which was attenuated to 1.26 (95% CI: 0.95-1.67, P = 0.108) by further adjustment of cruciferous vegetables consumption and obesity, with a mediation effect of 17.8% (95% CI: 2.9%-60.9%; P = 0.069). Conclusion: Bitter taste sensitivity was associated with less consumption of cruciferous vegetables and a high likelihood of obesity, which may mediate its association with diabetes.

Oral Exposure to Sodium Chloride without Subsequent Consumption Does Not Alter Salt Taste Function in Adults: A Cross-Over Intervention Study

BackgroundReduction in dietary sodium increases salt taste sensitivity; however, non-oral sodium supplementation does not, suggesting that oral exposure is more important for modulating taste perception than consumption without tasting. ObjectiveUsing psychophysical methods, we assessed the effect of a two-week intervention involving oral exposure to a tastant without consumption on modulating taste function. MethodsIn a cross-over intervention study, n = 42 adults (age, mean ± SD: 29.7 ± 8.0 years) completed 4 intervention treatments requiring participants to rinse their mouths with 30 mL of a tastant, 3 times daily for 2 weeks. Treatments included oral exposure to 400 mM sodium chloride (NaCl), monosodium glutamate (MSG), monopotassium glutamate, and sucrose. Participants’ taste function for salty, umami, and sweet [detection threshold (DT), recognition threshold (RT), and suprathreshold (ST)], and the glutamate-sodium discrimination status was evaluated before and after the tastant treatments. Effects of the interventions on taste function were assessed by using linear mixed models including treatment, time, and treatment x time interactions as fixed effects; significance was set at P > 0.05. ResultsThere was no treatment × time interaction on DT and RT for all tastes assessed (P > 0.05). The only change in ST was following the NaCl intervention, participants’ salt ST decreased at the highest concentration (400 mM) compared with the pre-NaCl treatment taste assessment (mean difference (MD): −0.052 [95% CI: −0.093, −0.010] labeled magnitude scale, P = 0.016). Compared with the pre-MSG treatment taste assessment, participants improved their ability to perform the glutamate-sodium discrimination task after the MSG intervention (MD:1.64 [95% CI: 0.395, 2.878] correct discrimination tasks, P = 0.010). ConclusionSaltiness of an adult’s free-living diet is unlikely to influence salt taste function, as oral exposure without consumption to a salt concentration greater than normally found in food, only attenuated taste responses to highly salty stimuli. This provides preliminary evidence that regulating salt taste function may require a coordinated response between oral activation and consumption of sodium.

Equivalent hazard magnitude scale

Abstract. Hazard magnitude scales are widely adopted to facilitate communication regarding hazard events and the corresponding decision making for emergency management. A hazard magnitude scale measures the strength of a hazard event considering the natural forcing phenomena and the severity of the event with respect to average entities at risk. However, existing hazard magnitude scales cannot be easily adapted for comparative analysis across different hazard types. Here, we propose an equivalent hazard magnitude scale to measure the hazard strength of an event across multiple types of hazards. We name the scale the Gardoni Scale after Professor Paolo Gardoni. We design the equivalent hazard magnitude on the Gardoni Scale as a linear transformation of the expectation of a measure of adverse impact of a hazard event given average exposed value and vulnerability. With records of 12 hazard types from 1900 to 2020, we demonstrate that the equivalent magnitude can be empirically derived with historical data on hazard magnitude indicators and records of event impacts. In this study, we model the impact metric as a function of fatalities, total affected population, and total economic damage. We show that hazard magnitudes of events can be evaluated and compared across hazard types. We find that tsunami and drought events tend to have large hazard magnitudes, while tornadoes are relatively small in terms of hazard magnitude. In addition, we demonstrate that the scale can be used to determine hazard equivalency of individual historical events. For example, we compute that the hazard magnitude of the February 2021 North American cold wave event affecting the southern states of the United States of America was equivalent to the hazard magnitude of Hurricane Harvey in 2017 or a magnitude 7.5 earthquake. Future work will expand the current study in hazard equivalency to modelling of local intensities of hazard events and hazard conditions within a multi-hazard context.

The traumatic consequences of Boko Haram slavery among the ethnic minorities of southern Borno, Borno State, Nigeria.

The investigation on the experiences of Kibaku ethnic minorities of southern Borno in the Federal Republic of Nigeria under the Boko Haram (BH) insurgency is inevitable, considering the dire humanitarian situation that has since prevailed. The mass massacre indicates the violation of human rights. To explore, describe and analyse the BH insurgency in north-eastern Nigeria and its traumatic effects which may be experienced at several interrelated levels. The research was conducted within the Kibaku ethnic communities of Chibok local government areas of Southern Senatorial District in Borno State of Nigeria. A predominantly exploratory and descriptive qualitative research design approach was adopted with a total of 80 participants. The health consequences of BH-inspired victimisation include sexually transmitted diseases such as AIDS and chronic infections, unwanted pregnancy, miscarriage and other reproductive health problems. The psycho-emostional effects are both incalculable and unquantifiable, which is compounded by grief for the loss of victims through either abduction or death. The unjustifiable mass violence against the minorities may, from a historical viewpoint, be an orchestrated suffering of humans at the hands of other 'humans' in north-eastern Nigeria.Contribution: This article will add to the body of knowledge considering the magnitude (scale) and implications (scope) of the genocidal violence meted by a motley of sectarian malcontents propagating some illogical, unscientific, and historically ideologies bothering on a combination of racial bigotry, ethnicity and religious intolerance in Nigeria.

Preferential Attraction Effects With Visual Stimuli: The Role of Quantitative Versus Qualitative Visual Attributes

Offering an inferior and rarely chosen third (decoy) option to decision makers choosing between two options has a paradoxical effect: It increases the choice share of the option most similar to the decoy. This attraction effect is robust when options are numeric but rarely occurs in humans when options are visual, even though it occurs in animals. Building on psychophysics, we examined two types of visual attributes: quantitative and qualitative. Quantitative visual attributes (e.g., different bottle volumes) can be perceived as magnitudes. Qualitative visual attributes (e.g., different colors), however, do not fall onto a magnitude scale. One can perceive that a bottle’s volume is twice that of another bottle but not that a green bottle’s color is twice that of a red bottle. We observed robust attraction effects for quantitative visual attributes (4,602 adults, 237 college-age participants), which reversed to repulsion effects when the visual attributes were qualitative (6,005 adults).

Tongue papillae density and fat taster status- a cardinal role on sweet and bitter taste perception among Indian population

Obesity is a complex nutritional disorder that may be influenced by calorie intake and eating behaviours. Aside from many studies, the influence of papillae count on obesity is still debated. Despite the multiple variables connected to weight gain and altered taste perception, determining the association between papillae count and taste sensitivity to fat, sweet and bitter tastes, in particular, has recently become a focus of attention. This study aimed to rule out the relationship between the number of papillae on different areas of the tongue and taste sensitivity in people (n = 150) among the various groups depending on their body mass index (BMI) and fat taste sensitivity. The general labelled magnitude scale (gLMS) was used for the taste sensitivity analysis, and participants were asked to rate the intensity of each concentration of the different tastants. Using a digital camera to obtain a picture of the tongue, the density of the papillae on the tongue was counted manually by three different operators. The study reveals that the total papillae density and BMI had a direct negative correlation (r = -0.43), with papillae density (PD) decreasing as BMI increased. Concurrently, persons with higher BMIs had lower papillae distributions (32.38 ± 1.85 PD/cm2) and significantly lower perceptions of the intensity of fat taste. Further examining papillae density in the anterior front part of the tongue, the front-right section, showed significantly higher papillae distribution (74.04 ± 2.11 PD/cm2) than the front-left section. When considering the sensitivity in the tip of the tongue, middle tongue, and whole mouth, high-sensitivity individuals for fat are more sensitive to both sweet and bitter tastes. Overall, the results of this study demonstrated a strong relationship between taste sensitivity in the Indian population, BMI, and tongue papillae density in various regions of the tongue.

Recommended b-Value for Computing Number of Equivalent Stress Cycles and Magnitude Scaling Factors for Simplified Liquefaction Triggering Evaluation Procedures

Recommended b-Value for Computing Number of Equivalent Stress Cycles and Magnitude Scaling Factors for Simplified Liquefaction Triggering Evaluation Procedures

Using Anisotropies as a Forensic Tool for Decoding Supernova Remnants

We present a method for analyzing supernova remnants (SNRs) by diagnosing the drivers responsible for structure at different angular scales. First, we perform a suite of hydrodynamic models of the Rayleigh–Taylor instability (RTI) as a supernova (SN) collides with its surrounding medium. Using these models we demonstrate how power spectral analysis can be used to attribute which scales in an SNR are driven by RTI and which must be caused by intrinsic asymmetries in the initial explosion. We predict the power spectrum of turbulence driven by RTI and identify a dominant angular mode that represents the largest scale that efficiently grows via RTI. We find that this dominant mode relates to the density scale height in the ejecta, and therefore reveals the density profile of the SN ejecta. If there is significant structure in an SNR on angular scales larger than this mode, then it is likely caused by anisotropies in the explosion. Structure on angular scales smaller than the dominant mode exhibits a steep scaling with wavenumber, possibly too steep to be consistent with a turbulent cascade, and therefore might be determined by the saturation of RTI at different length scales (although systematic 3D studies are needed to investigate this). We also demonstrate, consistent with previous studies, that this power spectrum is independent of the magnitude and length scales of perturbations in the surrounding medium and therefore this diagnostic is unaffected by “clumpiness” in the circumstellar medium.

Comparison of Bitterness Intensity between Prednisolone and Quinine in a Human Sensory Test Indicated Individual Differences in Bitter-Taste Perception.

Prednisolone is a frequently prescribed steroid with a bitter, unpalatable taste that can result in treatment refusal. Oral suspensions or powder dosage forms are often prescribed, particularly to pediatric patients, as they improve swallowability and ease of dose adjustment. Consequently, the bitterness of prednisolone is more apparent in these dosage forms. Few studies have investigated prednisolone's bitterness. Thus, in this study, 50 adults evaluated the bitterness of prednisolone using the generalized Labeled Magnitude Scale (gLMS), in comparison with quinine, a standard bitter substance. Overall, prednisolone-saturated solution demonstrated the same extent (mean gLMS score: 46.8) of bitterness as 1 mM quinine solution (mean gLMS score: 40.1). Additionally, large individual differences were observed in the perception of the bitterness of prednisolone and quinine. Perceived flavors of some drugs are reportedly associated with bitter-taste receptor (TAS2Rs) polymorphisms. Therefore, we investigated the relationship between subjects' genetic polymorphisms of TAS2R19, 38, and 46, and their sensitivity to bitterness. Although a relationship between TAS2R19 polymorphisms and the perception of quinine bitterness was observed, no significant relationship was found between the perceived bitterness of prednisolone and the investigated genes. Ultimately, the results show that despite individual differences among subjects, the cause of prednisolone's strong bitterness is yet to be elucidated.

Recovery of macrobenthic communities in tidal flats following the Great East Japan Earthquake

AbstractThe Great East Japan Earthquake, with a moment magnitude scale of 9.0M on March 11, 2011, caused huge tsunamis that altered aquatic communities in the nearshore ecosystems along the Pacific coastline of Sendai Bay, Japan. However, to understand the ecological implications of the tsunamis' impact, an assessment of the successive changes of the communities and their fate over time is essential. Therefore, we examined eight tidal flat communities of Sendai Bay with the aid of citizen volunteers over 9 years, and compared the microbenthic compositions to those before the earthquake. The results revealed that the differences in the community compositions caused by the tsunamis decreased from year to year and finally disappeared after 7 years except for one flat where the tsunamis largely changed the environmental conditions. The present study indicates that these tidal flat communities are regulated mainly by environmental conditions and are highly resilient to tsunami disturbance.

Accuracy and precision of frequency–size distribution scaling parameters as a function of dynamic range of observations: example of the Gutenberg–Richter law b-value for earthquakes

SUMMARY Many natural hazards exhibit inverse power-law scaling of frequency and event size, or an exponential scaling of event magnitude (m) on a logarithmic scale, for example the Gutenberg–Richter law for earthquakes, with probability density function p(m) ∼ 10−bm. We derive an analytic expression for the bias that arises in the maximum likelihood estimate of b as a function of the dynamic range r. The theory predicts the observed evolution of the modal value of mean magnitude in multiple random samples of synthetic catalogues at different r, including the bias to high b at low r and the observed trend to an asymptotic limit with no bias. The situation is more complicated for a single sample in real catalogues due to their heterogeneity, magnitude uncertainty and the true b-value being unknown. The results explain why the likelihood of large events and the associated hazard is often underestimated in small catalogues with low dynamic range, for example in some studies of volcanic and induced seismicity.

Investigation of resistive magnetic field generation by intense proton beams in dense plasmas

Current and future applications of intense proton sources abound, including radiography, cancer therapy, warm dense matter generation, and inertial confinement fusion. With increasingly efficient acceleration and focusing mechanisms, proton current densities may soon approach and exceed 1010 A/cm2, e.g., via intense laser drivers. Simulations have previously shown that in this current density regime, beam-induced field generation plays a significant role in beam transport through dense plasmas. Here, we present a theoretical model for the generation of resistive magnetic fields by intense proton beam transport through solid density plasmas. The theoretical evolution of the magnetic field profile is calculated using an analytic model for aluminum resistivity, heat capacity, and stopping power, applicable from cold matter to hot plasma. The effects of various beam and material parameters on the field are investigated and explained for both monoenergetic and Maxwellian proton beams. For a proton beam with Maxwellian temperature 5 MeV and total energy 10 J, the model calculates resistive magnetic fields up to 150 T in aluminum. The calculated field profiles from several beam cases are compared with 2D hybrid particle-in-cell simulations, with good agreement found in magnitude and time scale.

Revisiting b-value for extended Kopili region of Northeast India and probabilistic estimation of seismic hazard attributes thereof

Kopili fault and its' surroundings of northeast India have remained witness to some devastating earthquakes. The complex tectonic feature of this region incurs a high seismicity rate relative to other regions. Very recently, an earthquake of magnitude 6.4 (MW) has jolted this region. Considering the persistently rising seismicity pattern of this region, the present study intends to integrate the frequency magnitude distribution of earthquakes with other pertinent seismic hazard parameters. This work presents the estimation of the return period and probability of non-exceedance of medium to large earthquakes for the Kopili fault and its' surroundings via the extreme value method. Two statistical methods, namely the Gutenberg-Richter(G-R) power law and Gumbel extreme value method (GEVM), are applied for the correct estimation of the b-value for the Kopili fault and its' surrounding region. The uniform and homogenous magnitude scale dataset consisting of 550 events observed within a limit of 350 km from the Kopili fault (1964 to 2022) are used in the study. The b-value computed using GR relation was found to be unsatisfactory (0.73) due to an inadequate dataset—thus Gumbel's extreme value method is used for the estimation of the b-value (0.97). Gumbel's extreme value method is used for the calculation of the probability of occurrence of earthquakes, return period, and the most probable earthquake magnitude for the study region. The most probable annual earthquake is found to be ∼ MW 4.99. The return period and probability of occurrence of design-based earthquakes are also calculated. The correlation between b-value, seismic moment, and fractal dimension for seismic hazard analysis is also investigated. The antithetical relationship between seismic moment and b-value is observed for the region while the deep-root character of the Kopili fault and the strong, unfractured character of the Shillong plateau is highlighted with the spatial distribution of fractal dimension in the study region.

Local magnitude determination for Turkey from two independent seismic networks and a consistent M4 + catalogue

SUMMARY Turkish seismicity is routinely recorded by two broad-band seismic networks: the Turkish National Seismic Network (AFAD ‘TU’ network) and the Bogazici University Kandilli Observatory And Earthquake Research Institute (KOERI ‘KO’ network). Each of them has over 200 seismic stations distributed across the country. We obtain a new uniform and consistent local magnitude (Ml) scale for Turkey using data from both networks, as well as the M4 + catalogue with Ml values that results from applying said scale to the events that occurred between 2007 and 2016 within the country. We measure the half peak-to-peak amplitude of the vertical component seismograms and estimate the attenuation parameters through an iterative procedure that fits the logarithm of the amplitude as a function of the hypocentral distance, the local magnitude, the station corrections and a constant accounting for possible systematic differences between amplitudes measured on horizontal seismographs and those measured on vertical seismographs. We additionally scale Ml to the moment magnitude measured by an independent source, obtaining a magnitude relationship accounting for attenuation adjustments, as well as differences between maximum horizontal and vertical amplitudes. The estimated Ml formula shows that station corrections from both networks regionally agree, and that non-zero corrections are centred on zero, within −0.48 and 0.46 magnitude units (corresponding to the 2.5 and the 97.5 quantiles). The new M4 + catalogue with consistent Ml values for AFAD and KOERI shows magnitude residuals that cannot be explained by a Gaussian distribution. We also show a very good agreement between our new Ml value and the original Ml values of AFAD and KOERI, with median differences below 0.1 magnitude units.

Method for reconstruction of axisymmetric capillary wave surface topography using inverse ray-tracing of refracted laser sheet

Capillary waves can be used to measure the fundamental fluid properties such as surface tension as well as, potentially, the viscosity of Newtonian fluids. This requires the measurement of various wave parameters, mainly wavelength, amplitude, and decay coefficient. However, the different scales of magnitudes make it a challenging task. Optical methods are well suited to analyze such problems due to their non-intrusive nature and high dynamic measurement resolution in both space and time. These methods are further categorized as point methods for a single probe measurement and space–time methods for transient measurement of the complete surface. Dynamic space–time methods are preferred despite the associated complex post-processing since they enable reconstruction of the wave surface. Some existing methods are discussed, and an improved method is then proposed to actually solve the associated inverse optics problem. In the method, an axisymmetric wave surface is re-constructed by analyzing the refracted laser sheet. The assumptions, simplifications, and constraints are taken to be compatible with experimental aspects for future validation. It is derived using the fundamental concepts in physics and the only major assumption of the axisymmetric nature of wave surface. The method exploits the underlying symmetry in the topography, making it more versatile, and suited for linear and non-linear capillary waves and waves with planar wavefront. The impact of parameters on the final result is determined through numerical simulations. Very low error (average and maximum) values are observed between reference and reconstructed topography for damped and undamped wave surfaces with a wide range of curvatures. Optimum values of critical parameters and associated reasoning are presented.

Scaling analysis of price by multi-scale Shannon entropy

Multi-scale behaviors emerge in financial markets as complex systems. In this study, we intended to employ multi-scale Shannon entropy to trace the information transition of these phenomena, at different levels of Tehran stock market index (TEDPIX). The obtained results show that, in various magnitude scales and time scales, entropy Granger-causes TEDPIX index in terms of linear and nonlinear aspects. The results revealed that Granger causalities exist between entropy and TEDPIX. The causalities were linear in monthly (noise), quarterly (noise), semi-yearly (noise) and yearly (useful information) time spans; on the other hand, in quarterly (useful information) time span, the causalities were nonlinear. In this regard, one can conclude that entropy would be able to predict the market’s behavior.

The marsquake catalogue from InSight, sols 0–1011

The InSight mission (Interior Exploration using Seismic Investigations, Geodesy and Heat Transport) has been collecting high-quality seismic data from Mars since February 2019, shortly after its landing. The Marsquake Service (MQS) is the team responsible for the prompt review of all seismic data recorded by the InSight's seismometer (SEIS), marsquake event detection, and curating seismicity catalogues. Until sol 1011 (end of September 2021), MQS have identified 951 marsquakes that we interpret to occur at regional and teleseismic distances, and 1062 very short duration events that are most likely generated by local thermal stresses nearby the SEIS package. Here, we summarize the seismic data collected until sol 1011, version 9 of the InSight seismicity catalogue. We focus on the significant seismicity that occurred after sol 478, the end date of version 3, the last catalogue described in a dedicated paper. In this new period, almost a full Martian year of new data has been collected, allowing us to observe seasonal variations in seismicity that are largely driven by strong changes in atmospheric noise that couples into the seismic signal. Further, the largest, closest and most distant events have been identified, and the number of fully located events has increased from 3 to 7. In addition to the new seismicity, we document improvements in the catalogue that include the adoption of InSight-calibrated Martian models and magnitude scales, the inclusion of additional seismic body-wave phases, and first focal mechanism solutions for three of the regional marsquakes at distances ∼30°.

Magnitude relations between the teleseismic mb, the regional mR and Mw for intraplate earthquakes in Brazil

Magnitude conversions between different scales are important for comparison of seismic activity between different regions, homogenization of earthquake catalogs for seismic hazard calculations, and use of ground motion relations derived from other regions. Despite the trend of adopting Mw as the standard, reference magnitude scale, other scales are still much used for practical reasons and ease of calculation, such as the local ML for events detected by local networks, and short-period teleseismic mb for events in worldwide catalogues. In Brazil, a regional magnitude (mR), based on the maximum amplitude in the whole P-wave train recorded between 200 and 1500 km distance, has been adopted in our catalogues. The regional magnitude is equivalent to the teleseismic mb from 3.5 to 5.5.Empirical relations between the regional (mR), the teleseismic (mb) and the moment (Mw) magnitudes were determined for Brazilian intraplate earthquakes. Mw can be estimated from m by Mw = 1.10 m - 0.69. In this empirical relation, “m" is mb, mR, or the average of the two. However, despite the average consistency of the regional (mR) and teleseismic (mb) scales, it has been found that difference between mb and mR depend on the type of faulting mechanism: mb > mR for dip-slip earthquakes (reverse and normal faulting), and mb < mR for strike-slip events. This can be explained by the differences in the average radiation patterns of upper crustal earthquakes recorded at regional distances (more horizontally oriented take-off angles) or at teleseismic distances (more vertically oriented take-off angles). This brings the possibility to use the difference between regional and teleseismic magnitudes to indicate the probable type of focal mechanism.

An empirical test of groundwater pumping effects on river flow and temperature: Chemainus River case study

Groundwater abstraction from pumping wells can reduce the flows and water levels of hydraulically connected surface waters, which can affect aquatic communities and water rights of other users. Four pump tests were implemented in the 2016 summer low-flow period to measure groundwater pumping effects to Chemainus River surface water flow and temperature. The effect of pumping on surface flow was estimated using four metrics based on differences between measured and predicted flow at a hydrometric gauge located 340 m from the groundwater wells. Differences were estimated as residuals from a regression model relating flow at this gauge to flow at a gauge 1.3 km upstream of the wells. The effect of pumping on surface water temperature was assessed using daily maximum and daily average water temperature at gauges located 340 m and 1.4 km downstream of the wells. An effect of pumping on river flow was measurable when the pumps were turned on and shut off. The consistency of measured effects across all tests and the absence of discernable trends within and across tests indicate that the average effect of pumping across a broader period is equivalent to the average of all before and after comparisons, which was estimated as 9.9 L/s ± 12.1 L/s, or 5.5% of river discharge at the time of the tests. Groundwater pumping did not result in a detectable shift in water temperature. The results indicate that changes in water temperature in relation to the pump tests were smaller in magnitude or spatial scale than the detection limits of the implemented experimental design. This case study provides an example of quantification of pumping effects on stream flow and temperature, as required by the Water Sustainability Act for licensing of groundwater abstraction. We suggest this approach could be used elsewhere to quantify effects of groundwater abstraction.