Network Of Seismic Stations Research Articles

Characterizing Egyptian National Seismic Network station sites using genetic optimization for microtremor data inversion

Characterizing Egyptian National Seismic Network station sites using genetic optimization for microtremor data inversion

Seismic activity on the territory of Slovakia in 2022

The National Network of Seismic Stations of Slovakia (NNSS) consists of eight short period and six broadband permanent seismic stations and a data centre located at the Earth Science Institute of the Slovak Academy of Sciences (ESI SAS). The NNSS recorded and detected 11996 seismic events from all epicentral distances in 2022. Totally 76 earthquakes originated in the territory of Slovakia in 2022. This paper provides basic information on the configuration of the NNSS, routine data processing, seismic activity on the territory of Slovakia in 2022 as well as macroseismic observations collected in 2022.

Recent Expansion of the Cascades Volcano Observatory Geophysical Network at Mount Rainier for Improved Volcano and Lahar Monitoring

Abstract The U.S. Geological Survey Cascades Volcano Observatory (CVO) recently expanded its continuous geophysical monitoring at Mount Rainier, an active stratovolcano in Washington state. CVO monitors volcanoes in Oregon, Washington, and Idaho to characterize volcanic systems and detect unrest. Mount Rainier has a history of large lahar occurrences in the Holocene, including at least one that may not have been associated with volcanic activity. Pierce County, Washington, is one of the areas most at risk from large lahars. In the 1990s, CVO collaborated with Pierce County to install the Rainier lahar detection system (RLDS), an automated system designed to detect large lahars in high-risk drainages and mitigate hazards to heavily populated areas. The system was designed to detect lahars within 5–10 min of their occurrence and alert authorities of the need to evacuate populated low-lying areas before lahar arrival. In addition, CVO and the Pacific Northwest Seismic Network (PNSN) maintained and expanded a network of seismic and geodetic monitoring stations on and near the edifice to provide adequate volcano monitoring capabilities. Since 2016, CVO has worked to upgrade the existing RLDS and to expand its capabilities into other drainages around Mount Rainier. This expansion includes installation of 25 new broadband seismic stations with many including infrasound along high-risk drainages, as well as support for equipment upgrades at existing PNSN and CVO volcano monitoring sites. All stations transmit continuous, near-real-time data with dramatically improved spatial coverage for volcano monitoring and lahar hazard mitigation compared to the previous system.

Crustal structure beneath the Western Dharwar Craton segment of Western Ghats: Insights from ambient noise correlation technique

The Western Ghats (WG) comprise three major tectonic blocks: the Deccan Volcanic Province (DVP), Western Dharwar Craton (WDC) and Southern Granulite Terrain (SGT) from north to south. Among these, the WDC region encompasses the oldest basement rocks, including greenstone belts and calc-alkaline plutons dating back to ∼3.0 to 3.4 Ga. While the crustal structure of the DVP and SGT segments of the WG has been extensively studied, knowledge regarding the crustal structure beneath the WDC segment of the WG is limited due to the scarcity of seismic stations. To address this gap, we utilized continuous waveform data from a newly established network of seismic stations by the National Centre for Earth Science Studies (NCESS), in addition to other available stations and deciphered the shallow crustal shear-wave velocity structure along a profile beneath the WDC segment of the WG using ambient noise cross-correlation and surface wave dispersion. The results reveal a continuous upper layer characterized by a high shear wave velocity of ∼3.6 km/s with notable variation in thickness along the profile. Furthermore, a thick middle layer with velocities reaching up to ∼3.9 km/s and a lower layer with velocities of ≥4.2 km/s are observed. Intriguingly, variations in the thickness of the upper layer, ranging from 5 km to 20 km, are noted beneath the study region. The thickness of this layer exhibits changes in relation to topographical variations, with this dependency diminishing for deeper layers. Notably, high shear wave velocity perturbations (∼10 %) are observed in the upper layer beneath low-elevation regions, possibly indicating the presence of Tonalite–Trondhjemite–Granodiorite (TTG)-type gneiss − a significant rock type in the WDC region, alongside greenstone belts and late calc-alkaline to potassic plutons. These findings suggest that the uneven topography of the WG may result from long-term erosion, exposing deeper and higher-density rocks and leading to higher shear wave velocities at shallow depths. This study serves as a foundation for further exploration into the influence of the upper crustal layer and its correlation with the evolution of the WG.

Earthquake on January 24, 2024 near Krasnodar city, Mw=4.1, I0=5

The article presents instrumental and macroseismic data on the earthquake on January 24, 2024 at 11:19 (UTC), Mw=4.1, h=8 km. The earthquake parameters were determined using instrumental data from the network of regional seismic stations in the North Caucasus of the GS RAS. The earthquake parameters were determined from instrumental data from the network of regional seismic stations in the North Caucasus of the GS RAS. The source spectra of three regional seismic stations (GOYR, MRNR and GUZR) were calculated, from which the seismic moment М0, the stress drop Δσ and the source radius R were determined. The solution of the focal mechanism was obtained from the polarization in P-waves at 71 seismic stations and the type of source fault with a right-lateral strike-slip component. The epicentral zone of the earthquake on 24.01.2024 is located within the high-magnitude Akhtyrka zone of potential earthquake source zones (ESZ) with Mmax=6.5-6.8 and represents the boundary between the Northwestern part of the structures of the Greater Caucasus and the West Kuban trough. According to macroseismic survey in the regions, 300 respondents were interviewed in 20 settlements. The maximum observed intensity was I=V MSK-64.

The 2015 earthquake swarm in the Fentale volcanic complex (FVC): A geohazard risk for Ethiopia's commercial route to the Djibouti port.

We investigate rare seismicity in the neighborhood of the Fentale volcano, main Ethiopian rift that occurred in spring 2015 using data recorded by the Ethiopian Seismic Station Network. Over 1350 earthquakes are located and a seismic swarm is observed to the northeast of Fentale volcano, with the largest earthquake having a magnitude of 4.3 ML. Several VT (volcano-tectonic) and LP (long-period) events are observed in the swarm, indicating that it is induced by magmatic intrusion, consistent with dike-induced deformation in the same area inferred from satellite geodesy. The seismic activity commenced at about 40 km depth and migrated southwestward as it shallowed, towards Fentale volcano, suggesting that the dike feeding system might be influenced by the magma rich Afar Depression further to the northeast rather than the adjacent Fentale volcano. An earlier cluster of seismicity in the same area was recorded by a temporary deployment of seismic stations that ran from November 2001 to January 2003; extensive clusters of less well recorded seismic activity in the region occurred in June 1989, January–February 1981, October–November 2003, and 2004. Such frequent seismicity at the Fentale Volcanic Complex coupled with the adjacent fast-growing Lake Basaka poses an eminent and significant risk to Ethiopia's access to Djibouti port, its most important commercial route. This should be a wakeup call to concerned stakeholders to take precautionary measures by developing risk management and rapid response strategies.

Shake to the Beat: Exploring the Seismic Signals and Stadium Response of Concerts and Music Fans

Abstract Large music festivals and stadium concerts are known to produce unique vibration signals that resemble harmonic tremor, particularly at frequencies around 1–10 Hz. This study investigates the seismic signals of a Taylor Swift concert performed on 5 August 2023 (UTC) as part of a series at SoFi Stadium in Inglewood, California, with an audience of ∼70,000. Signals were recorded on regional seismic network stations located within ∼9 km of the stadium, as well as on strong-motion sensors placed near and inside the stadium prior to the concert series. We automatically identified the seismic signals from spectrograms using a Hough transform approach and characterized their start times, durations, frequency content, particle motions, radiated energy, and equivalent magnitudes. These characteristics allowed us to associate the signals with individual songs and explore the nature of the seismic source. The signal frequencies matched the song beat rates well, whereas the signal and song durations were less similar. Radiated energy was determined to be a more physically relevant measure of strength than magnitude, given the tremor-like nature of the signals. The structural response of the stadium showed nearly equal shaking intensities in the vertical and horizontal directions at frequencies that match the seismic signals recorded outside the stadium. In addition, we conducted a brief experiment to further evaluate whether the harmonic tremor signals could be generated by the speaker system and instruments, audience motions, or something else. All evidence considered, we interpret the signal source as primarily crowd motion in response to the music. The particle motions of the strongest harmonics are consistent with Rayleigh waves influenced by scattered body waves and likely reflect how the crowd is moving. Results from three other musical performances at SoFi in summer 2023 were similar, although differences in the signals may relate to the musical genre and variations in audience motions.

Crustal deformation in the vicinity of the Tan-Lu Fault Zone in East China constrained by receiver function analyses

To investigate the spatial distribution of crustal deformation and related geodynamic processes associated with the Tan-Lu Fault Zone (TLFZ) in East China, we measured crustal anisotropy based on the sinusoidal moveout of the P-to-S conversions from the Moho observed on receiver functions. Totally 142 well-defined crustal anisotropy measurements were obtained from the China National Seismic Network and other broadband dense seismic stations, including three stations exhibiting the pattern of a double layered anisotropy structure. The fast orientations observed at stations in the vicinity of the TLFZ were dominantly fault-parallel except for the southernmost part of the study area, where the fast orientations were approximately normal to the strike of the fault zone and may primarily be attributed to the NW-SE oriented Dabie Orogenic Belt. In the North China Block, NW-SE fast orientations were found to be consistent with the dominant orientation of the secondary faults. The Lower Yangtze Block showed two dominant fast orientations. The fault-parallel measurements in the west of the Jiangshao Fault Zone were controlled by the NE-trending faults in the Lower Yangtze Block, while the fast orientations in the east and south of the Jiangshao Fault Zone were dominantly E-W, which could be mainly influenced by the regional principal compressive stress. The average delay time of the entire study area was 0.27 ± 0.07 s. In the vicinity of the TLFZ where fault-parallel fast orientations were observed, an approximately 44% increase in delay time was observed, suggesting a well-developed fault zone.

Probabilistic location of early instrumental earthquakes based on macroseismic and instrumental data

There are regions of moderate seismicity that have long lacked a dense network of seismic stations due to their sparse population, inaccessibility, and low economic levels. Characterization of earthquakes in such regions is typically limited to the small amount of macroseismic information available and data from only one or two seismic stations. Most often, the location of such earthquakes was based on the use of macroseismic information alone. We propose a method for probabilistic estimation of the location of such earthquakes based on a joint analysis of their macroseismic and instrumental data. The technique is implemented in the ProLoM program (Probabilistic Locator by Macroseismics). In this study, we test the performance of the method on a test earthquake of May 20, 1967 and present the results of the analysis of the earthquakes that occurred in the north of the East European Platform on June 30, 1911 and January 13, 1939.

Toroidal mantle flow beneath the NE termination of the Kuril–Kamchatka subduction zone from seismic anisotropy

SUMMARY This study presents the findings of a splitting analysis conducted on core-refracted teleseismic shear waves (SKS, SKKS and PKS, called together as XKS) and local shear waves, obtained from a dense seismological network spanning the Kamchatka Peninsula. The objective of the study is to examine the pattern of mantle flow beneath the study area through the investigation of seismic anisotropy. The peninsula is situated at the northeastern end of the Kuril–Kamchatka subduction zone, where the Kuril trench intersects with the western boundary of the Aleutian trench. The data set utilized in this study comprises waveform data from a dense network of seismic stations (99 broad-band and short-period stations for the local shear wave splitting analysis and 69 broad-band stations for the SKS splitting analysis). The seismograms were downloaded from publicly available data repositories including the IRIS Data Management Center and the GFZ Data Services (GEOFON program). The dense station coverage allows us to investigate the lateral variations in anisotropy, providing insights into the flow patterns within the mantle. The processing of the combined data sets of local shear wave and teleseismic XKS waves allowed us to partially decipher the source of anisotropy in the mantle. Small delay (splitting) times (∼0.35 s) observed from the local-S data suggest that anisotropy in the mantle wedge is relatively weak with lateral variations. Larger splitting times (∼1.1 s) observed for the XKS waves relative to local S suggest that the main part of splitting on the XKS waves occurs in the subslab mantle. On the other hand, the rotational pattern of seismic anisotropy observed by both the local S and XKS waves suggests the presence of a toroidal flow at the NE edge of the subducting slab, which affects both the mantle wedge and subslab mantle. For the regions away from the edge of the slab, the mantle flow seems to be governed mainly by the drag of the lithospheric plate over the underlying asthenosphere.

SEISMICITY of the AMUR and PRIMORYE, SAKHALIN and the KURIL-OKHOTSK REGION in 2018-2019

A review of the Amur and Primorye, Sakhalin, and the Kuril-Okhotsk region seismicity for 20182019 is presented on the basis of data from the regional network of stationary seismic stations of the Sakhalin branch of the Geophysical Survey RAS with the involvement of data from adjacent seismological Russian and foreign agencies, as well as ten stations of the local network operating in the south Sakhalin. Parameters of 4989 seismic events have been determined, 193 of them are explosions. Focal mechanisms were calculated for 88 earthquakes. 116 earthquakes have shown a macroseismic effect. A map of the epicenters is presented, the distribution of the number N of crustal and deep-focus earthquakes by a magnitude, a total seismic energy ∑E for seismically active regions of three regions are given, in comparison with the average parameters N and ∑E for 20012017. For each region, an analysis of the parameters of the seismic regime in 20182019 is given in comparison with long-term averages, the maximum and significant seismic events are described. The seismicity of the Priamurye and Primorye, Sakhalin, and the Kuril-Okhotsk region in 20182019 can be characterized as a moderate one.

SEISMICITY of KYRGYZSTAN and UZBEKISTAN in 2018 and 2019

In 2018 and 2019 seismic observations on the territory of Kyrgyzstan and Uzbekistan were carried out by networks of seismic stations of these countries. In August 2018, the Salom-Alik station was added to the 25 seismic stations, functioning on the territory of Kyrgyzstan, and in April 2019, the Jany-Kuch station was installed. In 2018, 4 stations (Buston, Nukus, Sukok, Khiva) of 45 stations operating in the previous year in Uzbekistan were closed out. So, data of 41 seismic stations of Uzbekistan were used in 2018 and 2019. 2018 was relatively calm as regards to the seismic activity: the consolidated catalog of earthquakes included 231 events with KR=8.6–13.0. The maximum by energy was the earthquake of September 3 at 21h52m with KR=13.0, located at the territory of neighboring China. The foreshock close by energy was registered 73 seconds before it (KR=12.1). The main shock was accompanied by aftershocks, the maximum of which occurred on September 4 at 02h51m with KR=11.6. In 2019, the seismicity of the region remained almost at the level of the previous year: 210 earthquakes with KR=8.6–12.4 were registered. The strongest earthquake in this year's catalog occurred on January 12 with KR=12.4 also in China. The lowest seismic activity compared to its long-term average value for the period from 1996 to 2019 was noted in 2019.

SEISMICITY of AZERBAIJAN and ADJACENT TERRITORIES in 2018–2019

In 2018–2019, the Azerbaijan network of seismic stations continued to operate without changes and consisted of 35 digital stations. To estimate the magnitude of earthquakes in these years, only the local magnitude ML Azr was determined. The total number of earthquakes recorded by the Azerbaijan network of stations was 5387 in 2018 and 6880 in 2019, however, the catalog of earthquakes in Azerbaijan and adjacent territories, published in the appendix to this article, provides data on earthquakes only with a magnitude of ML Azr3.0, which ОБЗОР СЕЙСМИЧНОСТИ 66 number was 101 in 2018 and 115 in 2019. The number N of the representative level earthquakes (KR≥9) in the study area slightly increased in 2018 and 2019 compared to the long-term average annual value Nav for 1993– 2017, while the released seismic energy decreased relative to the background level by 6 and 7 times, respectively. The most significant seismic event on the territory of the Republic in 2018 was the earthquake of June 5 with ML Azr=5.5, and in 2019 – the earthquake of February 5, ML Azr=5.2. Both events were felt in the nearest settlements with an intensity of Ii=6.

SEISMICITY of NORTHERN EURASIA in 2018–2019

An overview of seismicity in 16 regions of Russia and neighboring countries in 2018–2019 is presented. Seismic monitoring of this territory was carried out by networks of seismic stations of Russia, Azerbaijan, Armenia, Belarus, Kazakhstan, Kyrgyzstan, Moldova, Turkmenistan, Tajikistan, Uzbekistan, Ukraine. In most regions, the seismic process occurred in the background. In Northern Eurasia as a whole, the total seismic energy in 2018 (Еan=17∙1016 J) remained unchanged compared to that for the previous year, and in 2019 fell to Еan=0.65∙1016 J, with annual values of released energy for 2018 and 2019 were significantly lower than its average annual level for the period 2006–2017. (Еan=5.3∙1016 J). The “Angular Uplift earthquake” on December 20, 2018 at 17h01m with MS=7.4 (MwGCMT=7.2), localized in the surface layer of the seismofocal zone of the Commander segment of the Aleutian arc with the epicenter in the Pacific Ocean was the strongest for the period 2018– 2019. Maximum shaking intensity on the tyerritory of Northern Eurasia (I=6–7) was caused by earthquake on July 6, 2018 at 01h40m with MwGCMT=6.2, h=75 km in the seismofocal zone of the Kuril Islands–Southern Kamchatka and Katav-Ivanovsk earthquake on September 4, 2018 at 22h58m in the Chelyabinsk oblast (Ural and Western Siberia region). The Katav-Ivanovsk earthquake is also unique in that it was accompanied by a significant number of aftershocks, which is the first known case for tectonic events within the Urals. In addition, it demonstrated that the natural seismic potential of the Urals exceeds the man-made component by orders of energy

Identification of natural and technogenic seismic events by energy characteristics

One of the key problems of seismic monitoring is the identification of earthquakes and signals from technogenic sources detected by a network of seismic stations. In peacetime, technogenic events are mainly associated with industrial mining developments, however, with the beginning of russia's full-scale aggression against sovereign Ukraine, thousands of seismic signals from explosions as a result of missile, aircraft, artillery strikes were registered by the seismological network of the Main Center of Special Monitoring of the State Space Agency of Ukraine. This significantly complicates the process of assessing seismicity and makes the question of determining the nature of registered events extremely relevant. Based on the analysis of seismic signals, the relationships between energy classes (K), magnitudes (mb), maximum amplitudes of longitudinal volumetric phases , and yields (Y) of explosions in TNT equivalent in Kyiv, Zhytomyr, Vinnytsia, Khmelnytsky, Chernihiv regions. Energy characteristics can be used to identify the nature of seismic events, and the results of the analysis of the ratios , , make it possible to yield estimate of explosions in TNT equivalent and determine the probable types of ammunition based on the received data. The energy from the signal source in the case of an explosive event can be determined additionally by infrasound data, the presence of an acoustic wave serves as an additional criterion for identifying the event. At the same time, energy characteristics make it possible to identify natural sources, an example of which is the tectonic earthquake of May 26, 2023 in the Poltava region.One of the key problems of seismic monitoring is the identification of earthquakes and signals from technogenic sources detected by a network of seismic stations. In peacetime, technogenic events are mainly associated with industrial mining developments, however, with the beginning of russia's full-scale aggression against sovereign Ukraine, thousands of seismic signals from explosions as a result of missile, aircraft, artillery strikes were registered by the seismological network of the Main Center of Special Monitoring of the State Space Agency of Ukraine. This significantly complicates the process of assessing seismicity and makes the question of determining the nature of registered events extremely relevant. Based on the analysis of seismic signals, the relationships between energy classes (K), magnitudes (mb), maximum amplitudes of longitudinal volumetric phases , and yields (Y) of explosions in TNT equivalent in Kyiv, Zhytomyr, Vinnytsia, Khmelnytsky, Chernihiv regions. Energy characteristics can be used to identify the nature of seismic events, and the results of the analysis of the ratios , , make it possible to yield estimate of explosions in TNT equivalent and determine the probable types of ammunition based on the received data. The energy from the signal source in the case of an explosive event can be determined additionally by infrasound data, the presence of an acoustic wave serves as an additional criterion for identifying the event. At the same time, energy characteristics make it possible to identify natural sources, an example of which is the tectonic earthquake of May 26, 2023 in the Poltava region.

New Insights Into the Active Tectonics of the Northern Canadian Cordillera From an Enhanced Earthquake Catalog

AbstractSeismic activity in the Northern Canadian Cordillera is characterized by diffuse earthquakes that extend hundreds of km northwest from the Yakutat collision zone. We use 25 months of broadband seismic data from Mackenzie Mountain Earthscope Project (MMEP), USArray Transportable Array (TA), and permanent Canadian National Seismic Network stations to present a local earthquake catalog with high sensitivity to small regional events. Deep learning techniques are adopted for both seismic phase detection and association. Event relocations are performed to provide well constrained estimates of earthquake depth distributions. Clusters of seismicity spanning the upper crust are located in the central Richardson Mountains, along the Tintina fault, and in the northeast Selwyn Basin. These clusters suggest that the core of the Richardson Anticlinorium is tectonically active and that the Tintina fault is a locus for low levels of active deformation. We interpret seismicity in the northeast Selwyn Basin as primarily occurring in the hanging wall of the Plateau thrust fault and suggest that some combination of localized duplex structures and lithological strength contrasts both within the Selwyn Basin and between abutting Paleozoic shelf sequences may be responsible for seismicity in the Mackenzie Mountain foreland.

Development of seismic monitoring in Kyrgyzstan

The data on the republican network of seismic stations continuously operating on the territory of Kyrgyzstan are presenting. The transition from analog to digital system of registration of seismic phenomena is considered as the next stage in the development of seismic monitoring in the republic.

A pre-seismic anomaly detection approach based on graph attention isomorphism network

Pre-seismic anomaly detection plays a crucial role in reducing economic losses and casualties caused by earthquakes. This paper proposes a novel four-step approach for pre-seismic anomaly detection. In the first step, a series of pre-seismic features are extracted by analyzing the earthquake catalog and geomagnetic signals. In the second step, the multi-view learning strategy is employed to obtain fusion features. In the third step, multiple seismic stations in one seismic zone are treated as a seismic station network, and a pre-seismic anomaly detection model is constructed based on the station network. In the final step, four evaluation indicators are introduced to comprehensively evaluate the detection results. Verification results show that the proposed method is effective and achieves better performance than other existing methods.

Tracking the Effect of Human Activity on MeSO-net Noise Using Seismic Data Traffic—Did Seismic Noise in Tokyo Truly Decrease during the COVID-19 State of Emergency?

Abstract Human activities cause seismic noise over 1 Hz (cultural noise), and the recent articles have reported that the curtailing of socioeconomic activities during the novel coronavirus (COVID-19) pandemic in 2020 appeared to reduce high-frequency seismic noise amplitudes in cities. The Tokyo metropolitan area in Japan, where seismic stations are densely distributed and various anthropogenic activities have been closely monitored, is an ideal study area to investigate the effect of human activity on high-frequency seismic noise during the pandemic. We demonstrated that the magnitude of seismic data traffic (SDT), indexed by the packet size of continuous seismic data in WIN32 format, is a good indicator for monitoring time-dependent changes in high-frequency noise levels. The SDT of 169 Metropolitan Seismic Observation network (MeSO-net) stations—a continuous accelerometer network that is mostly located at schools in the Tokyo metropolitan area—decreased by approximately 1%–3% from March to June 2020, when a state of emergency in Japan was first declared, compared with that in the previous year. We revealed that the SDT decrease was prominent only at stations near school buildings, and the SDT trend was uncorrelated with the temporal changes in the population and vehicular traffic volume near the seismic stations. We also found strong correlations between the SDT reduction and school size (classified by the number of students enrolled), implying that the noise decrease at the MeSO-net stations during the pandemic was strongly influenced by school-based activities. Thus, the noise reduction observed at MeSO-net stations during the COVID-19 pandemic in 2020 did not provide strong evidence of quieting in the Tokyo metropolitan area.

Sp converted waves reveal the structure of the lithosphere below the Alps and their northern foreland

SUMMARY The structure of the lithosphere is reflecting its evolution. The Moho of the European lithosphere has already been studied intensively. This is, however, not yet the case for the lower boundary of the lithosphere, that is the lithosphere–asthenosphere boundary (LAB). We are using S-to-P converted seismic waves to study the structures of the Moho and the LAB beneath Europe including the greater Alpine Area with data from the AlpArray project and the European networks of permanent seismic stations. We use plain waveform stacking of converted waves without deconvolution and compare the results with stacking of deconvolved traces. We also compare Moho depths determinations using S-to-P converted waves with those obtained by other seismic methods. We present more detailed information about negative velocity gradients (NVG) below the Moho. Its lower bound may be interpreted as representing the LAB. We found that the thickness of the European mantle lithosphere is increasing from about 50°N towards the Alps along the entire east–west extension of the Alps. The NVG has also an east dipping component towards the Pannonian Basin and the Bohemian Massif. The Alps and their northern foreland north of about 50°N are surrounded in the east, west and north by a north dipping mantle lithosphere. Along 50°N, where the NVG is reversing its dip direction towards the north, is also the area along which the volcanoes of the European Cenozoic Rift System are located. Our results possibly indicate that the Alpine collision has deformed the entire lithosphere of the Alpine foreland as far north as about 50°N.