Bulletin Data Research Articles

Selection of areas prospective for the search of primary hydrogen in the territory of Ukraine (based on the data of the 3D P-velocity model of the mantle)

The work aimed to identify promising areas for the search for primary hydrogen in Ukraine using a 3D P-velocity model of the mantle under Ukraine and its surroundings. The work uses a 3D P-velocity model of the mantle under the territory of Ukraine and its surroundings from a depth of 50 to 1700 km north of 50° NL and up to 2500 km to the south. The model is derived using ISC bulletin data from 1964 and is presented as horizontal and vertical cross-sections.
 Since the manifestation of hydrogen is primarily associated with the release of ultra-deep fluid tracks in the mantle, a brief analysis of them was presented. A detailed analysis of all nine superdeep mantle fluids isolated on the territory of Ukraine and their velocity characteristics was carried out. A comparison of the location of the routes of passage of superdeep fluids and the velocity structure of the mantle of the considered territory showed that they are confined to tectonically activated areas. In order to confirm the possible pre­sence of primary hydrogen in selected tracks of superdeep mantle fluids, heat flow density maps, a temperature map at a depth of 50 km, a map of the depth of the Moho boundary, a conductivity density map, and a fault map of the Ukrainian Shield were considered.
 A comparative analysis of maps of the location of superdeep mantle fluids and regions on the territory of Ukraine with increased heat flow, increased depth of the Moho boun­dary, and the presence of mantle conductors and faults was carried out. Summarizing the results of the comparative analysis, the most promising areas for the search for primary hydrogen were selected, corresponding to the following routes of superdeep fluids: f12, the northeastern part of f3, the southern part of f4 (the area of the Dnipro-Donetsk basin), the southwestern part of f1 (the area of the Western Ukrainian oil and gas-bearing region) and f9 and f10 (region of the South Crimean oil and gas-bearing province).

Effect of sunlight on vitamin D and hemoglobin levels among the residents of Ningbo, China.

Objective: this study investigated the effect of sunlight on vitamin D and hemoglobin levels among the residents of Ningbo, China. The impact of gender, age, and season on vitamin D and hemoglobin levels was also explored. Methods: a total of 8,481 research subjects, including 5,146 men and 3,335 women, who were permanent residents of Ningbo and received health checkups at Ningbo Second Hospital, were included in the study. Ningbo City climate bulletin data from 2019 to 2022 was also included. Results: the study subjects received an average of 132.20 ± 40.05 h of sunlight exposure per month and had average vitamin D levels of 19.63 ± 6.61 ng/ml. Hemoglobin levels were adequate in 85.4 % of the participants and deficient in 14.6 %. Sunlight exposure correlated positively with vitamin D and negatively with hemoglobin levels. Regression analysis indicated that gender, age, and season affected vitamin D and hemoglobin levels to different degrees. Conclusion: in Ningbo, vitamin D deficiency was common in adults while hemoglobin levels were mostly normal. The amount of sunlight exposure had a significant effect on vitamin D and hemoglobin levels and this relationship was impacted by gender, age, and season.

Two-Dimensional Attenuation and Velocity Tomography of Iran

Seismic bulletin data collected by the Iranian Seismological Center are used to image crust and mantle seismic attenuation, group velocity, and phase velocities for Lg, Pg, Sn, and Pn phases. This is possible because the peak amplitude time is picked, and amplitude measurements can be associated with the phase based on travel time plots. The group velocity is the apparent velocity of the maximum amplitude arrival and represents the combined effect of phase velocity and seismic scattering. Thus, it can be used in combination with the attenuation to identify where scattering attenuation is dominant. The Arabian–Iranian plate boundary separates low-velocity Zagros sediments from central Iran; however, in the mantle, it separates a high-velocity Arabian shield from central Iran. Scattering attenuation is low within the Arabian mantle and crust, and the Zagros sediments do not cause Lg or Pg attenuation. The Eocene Urumieh Dokhtar Magmatic Arc has high attenuation within both the crust and mantle, and while there is no partial melting in the crust, there may be some in the mantle. The northern Eocene Sistan Suture Zone shows particularly high attenuation that is accompanied by high scattering. It represents an incompletely closed ocean basin that has undergone intense alteration. The Alborz Mountains have high attenuation with some scattering.

Minimum 1D VP and VP/VS Models and Hypocentral Determinations in the Central Mediterranean Area

Abstract Minimum 1D velocity models and station corrections have been computed for the central Mediterranean area using two main data sets. The first one consists of accurate first arrival-time readings from 103 seismic events with magnitude (ML)≥3.5 recorded by the Italian National Seismic Network (RSN) and the AlpArray Seismic Network (AASN) in the period 2014–2021. Earthquakes were selected on the basis of their spatial distribution, epicentral distance to the nearest seismic station, and maximum distance traveled by Pn and Sn phases. This fine selection of high-quality data combined with the spatial density of the AlpArray seismic stations was decisive in obtaining high resolution for upper mantle velocity, especially in the Alpine belt. To obtain a denser coverage of crustal rays, we extended the first data set with P and S arrivals of local earthquakes from Istituto Nazionale di Geofisica e Vulcanologia (INGV) bulletin data (2016–2018). A total of 75,807 seismic phases (47,183 P phases and 28,264 S phases) have been inverted to calculate best-fit 1D velocity models, at regional and local scales. We then test the performance of the optimized velocity models by relocating the last four years of seismicity recorded by INGV (period 2017–2020). The computed velocity models are very effective for routine earthquake location, seismic monitoring, source parameter modeling, and future 3D seismic tomography.

Analysis of daily COVID-19 death bulletin data during the first two waves of the COVID-19 pandemic in Thiruvananthapuram district, Kerala, India.

Coronavirus disease 2019 (COVID-19) mortality trends can help discern the pattern of outbreak evolution and systemic responses. This study aimed to explore patterns of COVID-19 deaths in Thiruvananthapuram district from 31 March 2020 to 31 December 2021. Secondary data analysis of COVID-19 deaths in Thiruvananthapuram district was performed. Mortality data were obtained from the district COVID-19 control room, and deaths in the first and second waves of COVID-19 were compared. We summarised data as proportions and medians with the inter-quartile range (IQR) and performed Chi-square tests to make comparisons wherever applicable. As on 31 December 2021, 4587 COVID-19 deaths were reported in Thiruvananthapuram district, with a case fatality rate of 0.91%. We observed high mortality among older persons (66.7%) and men (56.6%). The leading cause of death was bronchopneumonia (60.6%). The majority (88.5%) had co-morbidities, commonly diabetes mellitus (54.9%). The median interval from diagnosis to hospitalisation was 4 days (IQR 2-7), and that from hospitalisation to death was 2 days (IQR 0-6). The deaths reported during the second wave were four times higher than those of the first wave with a higher proportion of deaths in the absence of co-morbidities (p < 0.001). The majority of the deceased were unvaccinated. Ecological analysis with vaccine coverage data indicated 5.4 times higher mortality among unvaccinated than those who received two vaccine doses. The presence of co-morbidities, an unvaccinated status, and delay in hospitalisation were important reasons for COVID-19 deaths. Primary level health providers can potentially help sustaining vaccination, expeditious referral, and monitoring of COVID-19 patients.

An Empirical Evidence of the Impact of Government Tax Revenue on Nigerian Public Debt

Objective The major objective of this paper is to examine the existence of a mutual consen-sus on the effect of tax revenue and non-tax revenue on public debt in Nigeria.Design/methodology – The study uses documentary research design. Data was collect-ed using secondary method of data collection from Debt Management office and Bureau of statistics and Central Bank of Nigeria statistical bulletin data bank. Ordinary Least Square Multi regression model was used in analyzing the dataResults – The research found out that there is a negative an insignificant relationship be-tween tax revenue, non-tax revenue and interest rate in relation to Nigerian public debt. Moreover, the paper found out that exchange rate and population rate had significant and positive relationship with Nigerian public debt.Limitation/Suggestion – The implication of the study is that, the contribution of tax revenue to the reduction of public debt is minimal as could be shown from the results. While, non-tax revenue contributed more than tax revenue in public debt reduction in Nigeria. In addition, increase in exchange rate, and population rate contributed more to increase in pub-lic debt, while, an increase in interest rate does not increase public debt but rather it discour-ages the government from collecting more debt and push the government to go for other rev-enue sources that where not assessed. The study recommended that; government should harness untapped taxes to increase tax revenue generation to pay interest on loan and princi-pal. Must of the information at the researcher disposal used for the study was for 15 years, from 2003 to 2018. Thus, studies need to be conducted involving more year like from 20 years upward to see whether it will change the result.Novelty/Originality – The originality of this research lies on the government inability to generate enough tax revenue and non-tax revenue to meet expenditure without collecting debt. This is because collection of debt always leads to frequent increase in debt burden in Nigeria. Fewer or no one has carried out a careful analysis of the relationship between tax and non-tax revenue against total debt in Nigeria.

Earthquake location in tectonic structures of the Alpine Chain: the case of the Constance Lake (Central Europe) seismic sequence

A set of four magnitude Ml ≥ 3.0 earthquakes including the magnitude Ml = 3.7 mainshock of the seismic sequence hitting the Lake Constance, Southern Germany, area in July–August 2019 was studied by means of bulletin and waveform data collected from 86 seismic stations of the Central Europe-Alpine region. The first single-event locations obtained using a uniform 1-D velocity model, and both fixed and free depths, showed residuals of the order of up ± 2.0 s, systematically affecting stations located in different areas of the study region. Namely, German stations to the northeast of the epicenters and French stations to the west exhibit negative residuals, while Italian stations located to the southeast are characterized by similarly large positive residuals. As a consequence, the epicentral coordinates were affected by a significant bias of the order of 4–5 km to the NNE. The locations were repeated applying a method that uses different velocity models for three groups of stations situated in different geological environments, obtaining more accurate locations. Moreover, the application of two methods of relative locations and joint hypocentral determination, without improving the absolute location of the master event, has shown that the sources of the four considered events are separated by distances of the order of one km both in horizontal coordinates and in depths. A particular attention has been paid to the geographical positions of the seismic stations used in the locations and their relationship with the known crustal features, such as the Moho depth and velocity anomalies in the studied region. Significant correlations between the observed travel time residuals and the crustal structure were obtained.

Variations of groundwater storage in different basins of China over recent decades

As an important freshwater resource, groundwater is of great significance to agriculture, industry, and daily life. The investigation of groundwater storage (GWS) in different regions of China is critical for water resource management and conservation. However, previous studies used different methods and data to monitor GWS in different regions of China, which made their results difficult to compare and cross validate. Here, we used a unified method by the Gravity Recovery and Climate Experiment (GRACE) satellite data and global models to study the variations of GWS in 10 major basins in China from April 2002 to December 2016. Results showed that GWS in the i) Songhua River basin (SRB), Liao River basin (LRB), Haihe River basin (HRB), Yellow River basin (YRB), Huaihe River basin (HHRB), and southeast basin (SEB) exhibited decreasing trends, ii) Yangtze River basin (YZRB) and Pearl River basin (PRB) presented increasing trends, and iii) southwest basin (SWB) and continental basin (CB) displayed both decreasing and increasing trends during the study period. These results were validated by comparing them with a large number of previous studies, which revealed that they were accurate and reliable. Comparing with the climate data and bulletin data, the analysis of causes for these trends indicated that drought and irrigation water-use led to a decline in GWS in several basins of northern China. The decreasing trend of GWS in the SEB was related to water use for production, whereas groundwater recharge from precipitation drove the increasing trends of GWS in the YZRB and PRB. In contrast, the wide geographical areas and complex factors of the SWB and CB led to the increasing–decreasing trends of GWS. This study enriches the GWS for China over the past decade, especially for SEB, PRB, and CB with rare GWS information. It will be helpful for the country’s groundwater resource management and systematic water conservation.

Analysis of Water Resources Change and Water Use Structure in Shaanxi Province

This article analyzes the changes in water resources, water consumption, and water structure in Shaanxi Province, China from 2004 to 2018, based on the water resources bulletin data of Shaanxi Province. The results show that the inter-annual differences in the amount of water resources in Shaanxi Province in the past 15 years are obvious, and the change process of the amount of surface water resources is basically the same as that of the total amount of water resources. The amount of water resources varies greatly around 2012; the total amount of water used in Shaanxi Province and various types of water consumption have shown a significant upward trend. Among all types of water consumption, agricultural water consumption has the largest increase, with a linear trend rate of 38 million m3/a. The proportion of agricultural water used in various types of water shows a significant downward trend, and the proportion of domestic water and ecological water shows a significant upward trend.

Source parameters of the 1926 and 1927 Jersey earthquakes from historical, instrumental, and macroseismic data

English Channel Islands are located off Normandy coast of France within an intraplate area not associated with high seismicity rate and active tectonics. However, in July 1926 a damaging and well-documented earthquake occurred there, followed by a strongly felt event in February 1927. In this paper, we reprocess macroseismic observations, analog seismograms and bulletin data in order to re-appraise the location and magnitude of these two earthquakes. We find that the macroseismic epicentre of the 1926 Jersey earthquake is shifted to the East when compared with the location offshore South of Jersey given in both the French database SisFrance and the recent French catalog FCAT-17. Arrival-times from published data, together with our own onset-time readings, are processed in order to obtain probabilistic hypocentral locations. The maximum-likelihood instrumental epicentre of the 1926 event is located about 15 km East of Jersey Island (49.20°N, 1.82°W). This epicentre is well constrained within a 10 km radius area. The location of the 1927 epicentre is slightly south of Jersey, at a location similar to that of SisFrance, but this latter epicentre is less constrained as fewer observations are available (the Probability Density Function for the 1927 epicentre is relatively “diluted”). Focal depth remains very poorly determined for both the 1926 and 1927 events. Analysis of historical seismograms is also performed in order to determine both surface-wave and moment magnitudes, MS and MW. We find MS = 5.6 ± 0.2 for the 1926 event and MS = 5.0 for the 1927 event. Waveform fitting of some of the highest quality seismograms of the 1926 event gives us MW in the range [5.0, 5.5], depending on the chosen focal depth and focal mechanism. The 1927 Jersey earthquake is expected with an intensity magnitude MI about 0.6 smaller.

Crucial role of natural processes in detecting human influence on evapotranspiration by multisource data analysis

Estimation of human-induced evapotranspiration (ET) changes (e.g., irrigation) is critical for understanding terrestrial water and energy cycle in the Anthropocene. A few studies have detected human influence on ET through comparing natural ET from reanalysis models and actual ET estimated by the water budget analysis with Gravity Recovery and Climate Experiment (GRACE) terrestrial water storage data. However, whether models can reasonably reproduce natural hydrological processes is overlooked. Here we show that uncertainty in model-simulated natural ET can determine whether the human-induced ET change is detectable. The naturalized runoff provided by the Yellow River Conservancy Commission is used to calibrate the Variable Infiltration Capacity (VIC) model to obtain a more reliable estimation of natural ET. The actual ET is estimated by either using the GRACE satellite retrievals with coal mining-induced gravity change removed, or 192 soil moisture station observations combined with surface and ground water resources bulletin data over the Yellow River basin. By comparing with natural ET from VIC simulations, human-induced annual ET changes are 41 ± 23 to 59 ± 31 mm/year during 2003–2010 for GRACE and soil moisture-based estimations respectively, contributing to 11%–16% increase in annual ET over the Yellow River basin. The estimation is comparable to the bulletin data of 47 mm/year. There is an obvious overestimation in natural ET from Global Land Data Assimilation System, prohibiting the detection of anthropogenic influence. This study highlights the importance of reasonably modeling natural hydrological processes as a baseline for detecting anthropogenic influence on the hydrological cycle.

Correlation Analysis Between Groundwater Decline Trend and Human-Induced Factors in Bashang Region

In Northern China, many regions and cities are located in semi-arid regions, and groundwater is even the only source of water to support human survival and social development. Affected by human activities, the Bashang (BS) region (including Zhangjiakou City and part of Xilin Gol League) have showed a significant decline in groundwater levels in recent years. However, in the BS region, the causes for the decline in groundwater level were not clear. In this study, we used time series of multi-source data Moderate Resolution Imaging Spectroradiometer (MODIS), Gravity Recovery and Climate Experiment (GRACE) and Global Land Data Assimilation System (GLDAS) to analyze vegetation and groundwater changes based on linear regression models. The variation trends of NDVI (Normalized Difference Vegetation Index, derived from MODIS) and GWSA (groundwater storage anomaly, derived from GRACE and GLDAS) indicated the increasingly better vegetation in the agriculture planting areas, partially degraded vegetation in the grassland, and the declining groundwater level in the whole study region. In order to assess the impact of human-induced factors on vegetation and groundwater, the R U E s e a s o n a l calculation model was proposed based on RUE (rain use efficiency) in this study. The R U E s e a s o n a l calculation results showed that human-induced factors promoted the growth of vegetation in agricultural areas and accelerated the consumption of groundwater. In addition, we also obtained temporal and spatial distributions of human activities-affected regions. The area affected by human-induced factors in the south-central study area increased, which accelerated the decline in groundwater levels. From bulletin data, we found that the increasing tourists and vegetable production are respectively the most important factors for the increased consumption of urban water and agricultural water. Based on multi-source data, the influences of various human-induced factors on the ecological environment were explored and the area affected by human-induced factors was estimated. The results provide the valuable guidance for water resource management departments. In the BS region, it is necessary to regulate agricultural water use and strengthen residential water management.

A reappraisal of the 1978 Ferruzzano earthquake (southern Italy) from new estimates of hypocenter location and moment tensor inversion

The March 11th, 1978 Ferruzzano earthquake is the most recent moderate-to-major earthquake occurred in the southern Calabrian region (southern Italy), one among the highest seismic risk areas of the whole Mediterranean. Previous information available from the literature on the 1978 earthquake is quite contrasting and not well framed in the regional seismotectonic scenario. In the present study we selected and digitized analog seismograms coming from stations of the Euro-Mediterranean region to invert for the deviatoric seismic moment tensor through a time-domain algorithm properly implemented to analyze data recorded before the advent of the digital era. Moreover, we estimated a new hypocentral location by using original bulletin data and a non-linear probabilistic earthquake location technique working with 3D velocity models. The quality and stability of the obtained results, both for hypocenter location and moment tensor inversion, were accurately checked by several inversion tests. Our results indicate that the 1978 earthquake (i) occurred westward and at a shallower depth respect to previous hypocenter locations, (ii) is characterized by a ca. N-S trending normal faulting mechanism and (iii) has a moment magnitude of 4.7, thus suggesting an overestimate of previous evaluations. This study furnishes new information on the 1978 Ferruzzano earthquake allowing to better frame it in the regional seismotectonic scenario and also proves that the time-domain waveform inversion algorithm applied to digitized old seismograms is capable to successfully invert also Mw < 5 earthquakes. The obtained results pave the way for future analyses of the early instrumental seismicity potentially capable to furnish new constraints to local and regional seismotectonic modeling.

Revision of earthquake hypocentre locations in global bulletin data sets using source-specific station terms

Revision of earthquake hypocentre locations in global bulletin data sets using source-specific station terms

Seismic network detection probability assessment using waveforms and accounting to event association logic

The geographical area where a seismic event of magnitude M ≥ Mt is detected by a seismic station network, for a defined probability is derived from a station probability of detection estimated as a function of epicentral distance. The latter is determined from both the bulletin data and the waveforms recorded by the station during the occurrence of the event with and without band-pass filtering. For simulating the real detection process, the waveforms are processed using the conventional Carl Johnson detection and association algorithm. The attempt is presented to account for the association time criterion in addition to the conventional approach adopted by the known PMC method.

Increase in cases of malaria in Mozambique, 2014: epidemic or new endemic pattern?

ABSTRACTOBJECTIVE To describe the increase in cases of malaria in Mozambique.METHODS Cross-sectional study conducted in 2014, in Mozambique with national weekly epidemiological bulletin data. I analyzed the number of recorded cases in the 2009-2013 period, which led to the creation of an endemic channel using the quartile and C-Sum methods. Monthly incidence rates were calculated for the first half of 2014, making it possible to determine the pattern of endemicity. Months in which the incidence rates exceeded the third quartile or line C-sum were declared as epidemic months.RESULTS The provinces of Nampula, Zambezia, Sofala, and Inhambane accounted for 52.7% of all cases in the first half of 2014. Also during this period, the provinces of Nampula, Sofala and Tete were responsible for 54.9% of the deaths from malaria. The incidence rates of malaria in children, and in all ages, have showed patterns in the epidemic zone. For all ages, the incidence rate has peaked in April (2,573 cases/100,000 inhabitants).CONCLUSIONS The results suggest the occurrence of an epidemic pattern of malaria in the first half of 2014 in Mozambique. It is strategic to have a more accurate surveillance at all levels (central, provincial and district) to target prevention and control interventions in a timely manner.

The ISC-GEM Global Instrumental Earthquake Catalogue (1900–2009): Introduction

In this introductory article we give a general description of the ISC-GEM Global Instrumental Earthquake Catalogue (1900–2009). We also provide the background for four further articles that describe the effort in collecting and digitizing parametric earthquake bulletin data as well as the methodologies developed to compute homogeneous earthquake parameters.The result of the two and a half year project is a catalogue of approximately 20,000 large earthquakes covering 110years with hypocentres and uncertainties computed using the same technique and velocity model. We show that the overall homogeneity of the main earthquake parameters in the catalogue was achieved despite changes in instrumentation and routine measurement practices concurrent with developments in instrumental seismology from almost a ground level to its current state.For each earthquake, MW magnitude values and uncertainties were computed either based on available estimates of seismic moment or using new empirical relationships between MW, MS and mb. Further important results of this project include the electronic availability of a considerable volume of seismic wave arrival time and amplitude measurements from early instrumental printed station bulletins. These newly recovered amplitude measurements provided a basis for computation of many previously unavailable MS magnitudes with uncertainties.In this article we describe why such a catalogue is required for a comprehensive assessment of global and regional seismic hazard. We also describe other potential uses of the catalogue in many other fields of Earth Sciences. We discuss the catalogue availability and lay out the plans of further development.

ISC-GEM: Global Instrumental Earthquake Catalogue (1900–2009), I. Data collection from early instrumental seismological bulletins

In order to produce a new global reference earthquake catalogue based on instrumental data covering the last 100+years of global earthquakes, we collected, digitized and processed an unprecedented amount of printed early instrumental seismological bulletins with fundamental parametric data for relocating and reassessing the magnitude of earthquakes that occurred in the period between 1904 and 1970. This effort was necessary in order to produce an earthquake catalogue with locations and magnitudes as homogeneous as possible. The parametric data obtained and processed during this work fills a large gap in electronic bulletin data availability. This new dataset complements the data publicly available in the International Seismological Centre (ISC) Bulletin starting in 1964. With respect to the amplitude-period data necessary to re-compute magnitude, we searched through the global collection of printed bulletins stored at the ISC and entered relevant station parametric data into the database. As a result, over 110,000 surface and body-wave amplitude-period pairs for re-computing standard magnitudes MS and mb were added to the ISC database. To facilitate earthquake relocation, different sources have been used to retrieve body-wave arrival times. These were entered into the database using optical character recognition methods (International Seismological Summary, 1918–1959) or manually (e.g., British Association for the Advancement of Science, 1913–1917). In total, ∼1,000,000 phase arrival times were added to the ISC database for large earthquakes that occurred in the time interval 1904–1970. The selection of earthquakes for which data was added depends on time period and magnitude: for the early years of last century (until 1917) only very large earthquakes were selected for processing (M⩾7.5), whereas in the periods 1918–1959 and 1960–2009 the magnitude thresholds are 6.25 and 5.5, respectively. Such a selection was mainly dictated by limitations in time and funding. Although the newly available parametric data is only a subset of the station data available in the printed bulletins, its electronic availability will be important for any future study of earthquakes that occurred during the early instrumental period.

Evaluating Water Environmental Conditionality for Tourism of National Scenic - A Case of Chaohu Lake, China

The paper collected bulletin data and literature information for fuzzy evaluation and quantitative analysis. Fuzzy evaluation was to compare the physical-chemical properties of Chaohu lake in China with the water tourist standards. Physical-chemical properties included water depth, temperature, flow, transparency, PH and floating materials, etc. Water tourist standards included natural swimming, yacht, diving, surfing, water-skiing and fishing, etc. The result shows the water quality of Chaohu lake restricts the development of the water tourist entertainment. Quantitative analysis was to calculate the loss rate due to water pollution of Chaohu lake. The water tourist function included three aspects about swimming, tourism and living. Pollutants index had BOD5,TN,TP, As, Hg, Cd and Pb. The result shows the water pollution makes swimming loss, tourism serious damage, living middle damage, comprehensive function serious damage. Main reason is that total nitrogen (TN) and total phosphorus (TP) exceed the standard. Lake tourism should consider water tourist environmental conditionality and functional applicability.

Bias Problems in Existing Teleseismic Travel Time Databases: Ignore or Repair?

An increasing number of earth scientists use teleseismic data for investigations of local, regional, and global geoscientific problems. The open access to global data makes this possible also for scientists outside the formal and informal communities of seismologists who produce and quality‐control these global data sets. In order to investigate the crust and upper mantle structure in the region of southern Scandinavia, Europe, we acquired waveform data from temporary stations contributed by several European instrument pools. The mobile station arrays were deployed in different time intervals (Fig. 1). One of the investigation methods was absolute travel time tomography. Here, we discuss some specific problems and their remediation in connection with tomographic inversion of teleseismic travel times when data from both permanent and moving temporary arrays are combined. Figure 1. Study area of southern Scandinavia with permanent and temporary seismological stations analyzed for tomographic velocity modeling (Medhus et al. , 2012). The non‐permanent arrays, marked with closed‐symbol markers, were deployed in different projects for 1–2 years covering about 10 years all together. The bold dashed outline shows the first case area of data for Figures 2 and 4. Stations studied in the second case are indicated by name boxes. Teleseismic travel times, defined as the difference between phase arrival time at the seismometer and the hypocenter time, are prone to errors of several kinds. These errors contaminate velocity modelling, such as tomographic inversion. Uncorrelated errors tend to average out, and therefore it has been very popular to take in massive data sets like the International Seismological Centre (ISC) (2001), Bulletin data (e.g., Widiyantoro et al. , 1997, Bijward et al. , 1998, Weidle et al. , 2005). However, bias errors do not average out. We discuss two sources of bias error in teleseismic …