Wireless valley, silicon wadi and digital island--Helsinki, Tel Aviv and Dublin and the ICT global production network

Hyper-capitalism in global information and communication technology (ICT) markets during the late 1990s created a new global production network, shaped by multinational corporations, international capital flows, and a flourishing of high-tech entrepreneurship. Each of the cities considered here benefited substantially from this growth, but their positions as nodes in the ICT global production network differed markedly, as did their ability to appropriate the value they generated. In Dublin, value creation was based largely on inward technology and capital flows, although indigenous Dublin-based software companies did demonstrate their ability to compete internationally. ICT development in Helsinki and Tel Aviv drew more strongly on the local knowledge base, and benefited from changes in national regulatory and political conditions. In Helsinki, public and private R&D investments supported the highly effective globalisation strategy of Nokia to create a strongly localised, vertically-integrated and strongly specialised sector. Value creation in the more diverse Israeli ICT sector was also based primarily on locally developed technology, university R&D and the commercialisation of technology developed initially for military applications. By the end of the 1990s, the resulting ICT node in Tel Aviv was grounded in the local knowledge-base, technologically diverse, strongly entrepreneurial and globally oriented.     

Focal mechanisms of three earthquakes in Finland and their relation to surface faults

Focal mechanisms for three recent earthquakes in Finland are determined using P-wave polarities together with SV/P and SH/P phase amplitude ratios. The events occurred on May 11, 2000 in Toivakka, Central Finland (M_L=2.4), on September 15, 2000 in Kuusamo, northeastern Finland (M_L=3.5), and on May 2, 2001 in Kolari, western Finnish Lapland (M_L=2.9).In order to obtain reliable estimates of the source parameters, one-dimensional crust and upper mantle velocity models are derived for the epicenter areas from deep-seismic sounding results. The starting models are modified by one-dimensional ray tracing using the earthquake observations. The events are relocated by employing P- and S-phase arrival times from the nearest seismic stations and the final velocity models. Synthetic waveforms, calculated with the reflectivity method, are used to further constrain and verify the source and structural parameters.The Toivakka earthquake indicates thrust- or reverse-faulting mechanism at a depth of 5 km. After comparison with aeromagnetic and topographic data we suggest the eastward dipping nodal plane (358°/42°) was the fault plane. The best-fitting fault plane solution of the Kolari earthquake suggests pure thrust-faulting at a depth of 5 km. The nodal plane striking 035°/30° correlates well with surface observations of the postglacial, possibly listric fault systems in the source area. The Kuusamo earthquake (focal depth 14 km) has a normal-faulting mechanism with the nodal planes trending 133°/47° or 284°/47°. Preference is given to the SW-dipping nodal plane, as it seems to coincide with topographic and magnetic lineament directions that have been active after the last ice age.The three earthquakes have occurred in old Precambrian faults and shear zones, which have been reactivated. The reactivated faults are favourably oriented in the local stress field.     

Precious metal mineralisation in the Sotkavaara Intrusion,northern Finland: Peak Pt,Pd, Au and Cu offsets in a small intrusion with poorly-developed magmatic layering

The Sotkavaara Intrusion is a small (2.5 × 1.5 km surface expression) mafic-ultramafic intrusion located in northern Finland, 25 km east-southeast of Rovaniemi. The intrusion was drilled by the Geological Survey of Finland between 2009 and 2012, when low-S, low-grade precious metal mineralisation (<1.1 ppm Pt + Pd + Au) was discovered. Emplaced into the 1.98 Ga eastern Peräpohja Schist Belt, Sotkavaara occurs a few tens of kilometres north of the 2.44 Ga the Penikat, Portimo and Koillismaa intrusions, which together host Europe’s most significant platinum-group element (PGE) mineralisation. The intrusion comprises a volumetrically subordinate Gabbro Unit and volumetrically dominant Pyroxenite Unit, within which layering is poorly-developed. The Pyroxenite Unit is composed predominantly of clinopyroxenite and contains a small number of laterally discontinuous wehrlite, olivine clinopyroxenite and low-Cr clinopyroxenite (<0.1 wt% Cr₂O₃) layers. Precious metal mineralisation is hosted by low-Cr clinopyroxenite layers and shows systematic Pt, Pd, Au and Cu offsets similar to those in the Munni Munni, Rincón del Tigre, Skaergaard and Great Dyke intrusions. Relative to these global examples, the Sotkavaara Intrusion represents an atypical occurrence, exhibiting poorly-developed modal layering in a small mafic-ultramafic intrusion, alongside moderately heavy δ ³⁴S values (+1.3 to +9.6‰). Despite this, mineralisation can be broadly attributed to similar ore-forming processes, whereby in-situ fractional crystallisation is ultimately responsible for generating small volumes of sulphide melt. Although mineralisation is sub-economic, this occurrence indicates that northern Finland may be prospective for magmatic sulphide deposits in Svecofennian-age mafic-ultramafic intrusions. Globally, Sotkavaara highlights that well-developed modal layering and large magma chambers are not necessarily requirements for forming this type of mineralisation.     

The isolation of Kruunuvuorenlampi, southern Finland, and implications for Holocene shore displacement models of the Finnish south coast

In the southern coastal area of Finland, many studies exist on shore displacements related to the higher Ancylus Lake and Litorina Sea altitudes. However, the late- Holocene shore displacement history is much less known and the shore displacement models are based on interpolations. Kruunuvuorenlampi, a small lake located at an altitude of 8.6 m a.s.l., was studied to test the reliability of the interpolated models. The cores revealed an unusual bottom lithostratigraphy, with a coarse gravel and sand layer sandwiched between the lower marine clays and upper shallow-water clay-gyttja. Analysis of diatoms, pollen and loss-on-ignition, together with radiocarbon datings, were carried out to determine and date the isolation event of the lake. The results show that the lake was isolated ca. 2400 ¹⁴C years BP and that the coarse grained layer was deposited prior to the isolation. The reconstruction of the emergence of the lake basin area suggests that the coarse grained layer originated from strong wave erosion of the shores before the isolation. This interpretation is supported by the presence of a wave-washed boulder belt on the NE slope of the basin. The isolation of Kruunuvuorenlampi lies exactly on the interpolated shore displacement model of the 30 m Litorina isobase. This placement suggests that no significant transgressions took place between the Litorina transgression and the isolation of Kruunuvuorenlampi.     

A case study of the impact of cyclonic trajectories on sea-level extremes in the Gulf of Finland

Modelling of water levels in the Baltic Sea, aimed at evaluating the influence of the trajectories and propagation speeds of a deep idealized cyclone on sea-level extremes in the Gulf of Finland, is done using the hydrodynamic model BSM6. An analytical expression for determination of the atmospheric pressure in this cyclone takes into account the existence of the cold front and the time evolution of the cyclone intensity. The empirical parameters in this relation are based on those of the deep cyclone ‘Erwin’ which passed over the Baltic Sea region in 2005.     

On the estuarine transport reversal in deep layers of the Gulf of Finland

The Gulf of Finland is a 400-km long and 48–135-km wide tributary estuary of the Baltic Sea featuring the longitudinal two-layer estuarine flow modified by transverse circulation. Longitudinal volume transport in the deep layer is investigated by decomposing it into an averaged, slowly changing estuarine component (due to large-scale density gradients, river discharge and mean wind stress) and wind-driven fluctuating component. The derived expression relates the total deep-layer transport to the projection of wind stress fluctuation to a site-specific direction. The relationship is tested and calibrated by the results from numerical experiments carried out with the three-dimensional baroclinic circulation model. For the entrance to the Gulf of Finland, winds from northeast support standard estuarine circulation and winds from southwest work against the density-driven and riverine flow. The deep estuarine transport may be reversed if the southwesterly wind component exceeds the mean value by 4–5.5 m s⁻¹. According to the data from hydrographic observations in the western Gulf of Finland, an event of advective halocline disappearance was documented in August 1998. Comparison of the deep-water transport estimates calculated from the wind data in 1998 with the observed salinity variations showed that the events of rapid decay of estuarine stratification were coherent with the estimated reversals of deep-layer volume transport, i.e. events of salt wedge export from the gulf.     

Magnetic fabric and emplacement of the post-collisional Pomovaara Granite Complex in northern Fennoscandia

The Proterozoic Pomovaara Granite Complex in northern Finland comprises three separate highly magnetic granite stocks. They are discordant, apparently unfoliated and according to isotope data, a significant Archaean component characterizes the source of these granites. The three stocks are aligned in an array parallel to major trans-crustal faults as interpreted from both aeromagnetic and gravity data. Their younger age of 1.8 Ga, compared to the main tectonic events at 1.9 Ga in northern Fennoscandia, indicates their post-collisional nature with respect to these events. The anisotropy of magnetic susceptibility (AMS) was studied together with magnetic, gravity and geological data in order to assess the emplacement mechanisms of the Pomovaara Granite Complex, and the possible tectonic control of fault systems on the ascent and emplacement of granitic magma. The orientation of magnetic fabrics within the granite stocks indicates that the direction of the original magma upwelling was from the SW, parallel to the major fault zones that controlled, at the crustal scale, the ascent of granite magmas. The predominant NW–SE orientations of the minimum magnetic axes of the magnetic ellipsoid and the elongate shapes of the stocks indicate compression normal to the deep fault trend during the crystallization of the granite magma.     

Recent environmental history of a large,originally oligotrophic lake in Finland: a palaeolimnological study of chironomid remains

The sedimentary chironomid stratigraphy in short-core samples covering approx. the past 150 years was studied in the northernmost basin of Lake Päijänne, southern Finland (62° 11 N, 25° 48 E). The basin has received effluent loading from the wood-processing industry and municipal waste water. Four developmental stages were distinguished based on the changes in chironomid assemblages: 1. Pre-industrial stage (dated by the²¹⁰Pb method as covering approximately the period 1838–1936), 2. Stage of increasing pollution (approx. 1944–1973), 3. The black decade, or the period of worst pollution (approx. 1973–1983), and 4. Water protection stage (approx. 1983 onwards).During the first stage the basin suffered very little human interference and was oligotrophic, with values of 4.00–4.28 for Wiederholm's Benthic Quality Index (BQI). During the second stage it altered between weak mesotrophy and moderate mesotrophy, and the former profundal assemblages characterized byHeterotrissocladius subpilosus andMicropsectra were replaced bySergentia coracina andChironomus anthracinus gr. The BQI ranged from 2.75 to 3.50. This process led to the extirpation ofH. subpilosus. Eutrophication of the basin reached its climax during the black decade, representing moderate eutrophy with a BQI of 2.15. The profundal assemblages were composed mainly ofChironomus anthracinus gr. andC. plumosus gr. The adoption of more effective waste water purification processes in both the wood-processing industry and the municipal treatment plant markedly reduced effluent loading, especially BOD loading during the fourth stage, and this led to a recovery in the basin. At present it is mesotrophic, with a BQI of 2.90–3.00, and its biological conditions resemble those of the second stage in the 1950's and 1960's.     

Pulp and paper mill pollution and subsequent ecosystem recovery of a large boreal lake in Finland: a paleolimnological analysis

Sedimentary diatom frustules and chironomid remains, in addition to the chemical stratigraphy of 32 elements and resin acids, were studied from short-core samples taken from two basins and a sheltered bay of Lake Päijänne in southern Finland (about 61 °10–62 °15 N, 25 °30 E). The lake was formerly oligotrophic but has been subject to effluent loading from pulp and paper mills during the past century since the opening of the first pulp mill in the 1880s. Four developmental phases were distinguished and named mainly according to the effects found in the basin close to the pollution source: (1) the pre-industrial phase (from the 1800s to ca. 1920), including the early years of industrialization, with low impacts; (2) the phase of increasing pollution (ca. 1920–1969); (3) the phase of severe pollution (1970–1981); and (4) the water protection phase (1982 onwards).Distinct differences were observed between pelagic (diatoms) and benthic (chironomid) ecosystems in their response to pollution. Effluent loading from the pulp and paper mills had a pronounced impact on chironomid assemblages, but only a slight influence on diatoms in the basin close to the pollution source. In the southern basin, approximately 60 km downstream, an increase in acidophilous species was observed in the diatom assemblages during the early years of pollution, but changes in chironomids in this basin were negligible. The water protection work of the past 30 years, which has led to an improvement in water quality and a marked recovery of the profundal biota, has also resulted in a slight increase in primary production of the lake. The decrease in brown-coloured effluent water has led to an increase in thickness of the lake's photic productive layer, while the toxicity of the water has simultaneously diminished. Rapid changes in chironomid assemblages and sedimentation observed in the sheltered bay highlight the importance of local land-use activities as causes of environmental change in this area, and especially their effects on sedimentation and benthic life.