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The paper reports on detection and quantification of the impact of local anthropogenic structures and regional climatic changes on subsurface temperature field. The analyzed temperature records were obtained by temperature monitoring in a borehole in PragueSpořilov (Czechia) and by repeated logging of a borehole in Šempeter (Slovenia). The observed data were compared with temperatures yielded by mathematical 3D time-variable geothermal models of the boreholes' sites with the aim to decompose the observed transient component of the subsurface temperature into the part affected by construction of new buildings and other anthropogenic structures in surroundings of the boreholes and into the part affected by the ground surface temperature warming due to the surface air temperature rise. A direct human impact on the subsurface temperature warming was proved and contributions of individual anthropogenic structures to this change were evaluated. In the case of Spořilov, where the mean annual warming rate reached 0.034°C per year at the depth of 38.3 m during the period 1993-2008, it turned out that about half of the observed warming can be attributed to the air (ground) surface temperature change and half to the human activity on the surface in the immediate vicinity of the borehole. The situation is similar in Šempeter, where the effect of the recently built surface anthropogenic structures is detectable down to the depth of 80 m and the share of the anthropogenic signal on the non-stationary component of the observed subsurface temperature amounts to 30% at the depth of 50 m.

Abstract. Two borehole climate observatories were established in Slovenia and Portugal within a joint CzechSlovenian-Portuguese project in the years [2003][2004][2005]. Together with the older Czech observatory, which has been operating since the year 1994, they monitor air, soil and bedrock temperatures with the aim of studying air-ground coupling and the downward propagation of the surface temperature changes. We report here on repeated temperature logs carried out within 6 boreholes at the sites of the observatories and their surroundings within a time span of 8-20 years . The repeated logs revealed subsurface warming in all the boreholes amounting to 0.2-0.6 • C below 20 m depth. The compatibility of the observed temporal changes of subsurface temperature with surface air temperature (SAT) series measured in Prague (since 1771), Ljubljana (since 1851) and Lisbon (since 1856) was checked by comparing repeated temperature logs with synthetic profiles that were calculated using SAT series as forcing functions. The depth of the Czech borehole (140 m) and the Portuguese borehole (180 m) was sufficient for a reconstruction of the ground surface temperature (GST) history of the last 150-200 years. Reconstructed GSTs were compared with the SAT series measured in Prague and Lisbon, respectively. The reconstructed histories reproduce reasonably well the amplitude of the recent warming inferred from the meteorological data, 1-1.5 • C above the long-term mean. The depth (100 m) of the four repeatedly logged Slovenian boreholes was too shallow for inversion, but a climatic reconstruction was carried out for a deeper borehole, logged in 2006 and located within 5 km from the Slovenian observatory. The obtained GST history was compared with SAT series from Ljubljana.

Periodic revisions of the Global Heat Flow Database (GHFD) take place under the auspices of the International Heat Flow Commission (IHFC) of the International Association of Seismology and Physics of the Earth's Interior (IASPEI). A growing number of heat-flow values, advances in scientific methods, digitization, and improvements in database technologies all warrant a revision of the structure of the GHFD that was last amended in 1976. We present a new structure for the GHFD, which will provide a basis for a reassessment and revision of the existing global heat-flow data set. The database fields within the new structure are described in detail to ensure a common understanding of the respective database entries. The new structure of the database takes advantage of today's possibilities for data management. It supports FAIR and open data principles, including interoperability with external data services, and links to DOI and IGSN numbers and other data resources (e.g., world geological map, world stratigraphic system, and International Ocean Drilling Program data). Aligned with this publication, a restructured version of the existing database is published, which provides a starting point for the upcoming collaborative process of data screening, quality control and revision. In parallel, the IHFC will work on criteria for a new quality scheme that will allow future users of the database to evaluate the quality of the collated heat-flow data based on specific criteria.

Large transboundary Upper Miocene geothermal sandy aquifers which are widely utilized by both countries for balneological and direct heat purposes exist in the Slovenian-Hungarian border region. In NE Slovenia the total direct heat use was 382 TJ in 2010, while in SW Hungary it was 648 TJ, including utilization from basement reservoirs. The total installed capacity of the 13 Slovenian users was 38.8 MW t , while that of the 29 Hungarian users was 70.6 MW t . Utilisation takes place without harmonized management strategies which might endanger the longterm sustainability of these systems. We aimed to overcome this by delineating a transboundary thermal groundwater body (TTGWB) Mura-Zala with an aerial extent of 4,974 km 2 and with vertical extent between depths 500-2,200 m, which was done based on detailed geological, hydrological, geochemical and geothermal models as well as numerical modelling. The regional groundwater flow in the Mura-Zala TTGWB is from west to east in general, the modeled cross-border flow is approximately 50 l/s. At present, thermal water abstraction rates from the Mura/ Újfalu Fm. (61.8 l/s in the Slovenian and 67.3 l/s in the Hungarian part of the TTGWB) does not endanger the good regional quantity status of the water body, and this should be maintained by allowing a maximum increase of thermal water abstraction 3.5 times higher than today. However, to achieve target numbers for an increased proportion of geothermal energy in the total energy mix in both countries, we suggest that increase of thermal efficiency and re-injection should be prioritized apart from the higher thermal water abstraction with setting up limit of the maximum allowable drawdown. Izvle~ekNa mejnem obmo~ju med Slovenijo in Madžarsko so razprostranjeni obsežni, prekomejni zgornjemiocenski geotermalni pe{~eni vodonosniki, ki se v obeh državah uporabljajo predvsem v balneolo{ke namene in za direktno rabo toplote. V severovzhodni Sloveniji je skupna direktna raba toplote v letu 2010 dosegla 382 TJ, v jugovzhodnem delu Madžarske pa 648 TJ, vklju~no z rabo vodonosnikov v podlagi neogenskih kamnin. Celotna in{talirana kapaciteta 13 slovenskih uporabnikov je zna{ala 38,8 MW t , medtem ko je in{talirana kapaciteta pri 29 madžarskih uporabnikih dosegla 70,6 MW t . Uporaba poteka brez usklajene strategije upravljanja, kar lahko ogrozi dolgoro~no vzdržnost teh sistemov. To smo želeli prese~i z opredelitvijo prekomejnega Mursko-Zalskega telesa termalne podzemne vode (VTPodV Mura-Zala) s povr{ino 4.974 km 2 in vertikalnim razponom globine 500-2200 m, dolo~enega na podlagi podrobnih geolo{kih, hidrogeolo{kih, geokemi~nih in geotermalnih modelov, kot tudi numeri~nega modela podzemne vode. Tok podzemne vode v VTPodV Mura-Zala je usmerjen pretežno v smeri zahod-vzhod, pri ~emer je prekomejni tok ocenjen na približno 50 l/s. Pri trenutni koli~ini odvzema termalne vode (~ 61,8 l/s iz slovenskega ter ~ 67,3 l/s iz madžarskega dela VTPodV Mura-Zala) koli~insko stanje telesa ni ogroženo, a njegovo dobro stanje je potrebno ohranjati ...

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