Mass movements in the area of Gdynia documented on old maps and in archival materials

The article deals with selected examples of old nautical maps (portolans), topographic maps, archival materials of the 19th century German language studies, which are valuable sources of information on the history of landslide processes. The city of Gdynia was founded in 1926, and its location despite very unfavourable formation of mass movements, was determined by economic and political reasons. As documented on nautical maps from 1596, landslides have been occurring in the coastal zone of today’s Gdynia since at least the 16th century. Within the limits of the zone, the oldest structural damage has been observed. The Urmesstischblätter map from 1837 documented damage to the redoubt in Cypel Oksywski. These fortifications, which were erected during Napoleonic Wars between 1810 and 1812, were completely rouined in the first half of the 19th century. It was the first time when mass movement resulted in financial losses in Poland’s coastal zones. Compared with the present, the 19th century saw an increase in mass movement activation in coastal zones. Between 1837 and 1909 the maximal changes in Cypel Oksywski were 2.2 m a year. The landslide in Cypel Oksywski is also the first stabilized landslide within the city limits of Gdynia. It also has the longest history of stabilizing efforts that go back to 1909. This article shows, based on the study of a landslide in Wielki Kackfrom 1930, that in the development of the city of Gdynia virtually from the beginning of its foundation in 1926, man-made dangerous gravitational processes have always been present

In the footsteps of amber mining in the Pomeranian province

W artykule przedstawiono na podstawie analizy archiwalnych materiałów kartograficznych oraz literatury polsko- i niemieckojęzycznej z okresu XVI–XXI wieku rozmieszczenie dawnych kopalni bursztynu w województwie pomorskim. Rejestr dawnych wyrobisk opracowano w oparciu o technologię GIS. W efekcie wyznaczono 32 nieznane do tej pory historyczne miejsca wydobywania bursztynu. Na podstawie badania źródeł kartograficznych: XIX i XX-wiecznych pruskich map topograficznych w skali 1:25 000 (Urmesstischblätter, Messtischblätter) i arkuszy mapy geologicznej Prowincji Prusy w skali 1:100 000 (Geologische Karte der Provinz Preußen) uszczegółowiono lokalizację 11 historycznych stanowisk górniczych. W wielu przypadkach z jednym miejscem skojarzonych było więcej kopalni bursztynu. W rezultacie badanie archiwalnych pruskich map topograficznych umożliwiło dokładną lokalizację 35 dawnych kopalni bursztynu. Dodatkowo XIX-wieczne pruskie mapy geologiczne w skali 1:100 000 wizualizują lokalizację 9 kopalni. Analiza materiałów historycznych i przeprowadzone w terenie rozpoznanie wskazuje na relikty dawnego górnictwa bursztynowego szczególnie cenne z punktu widzenia dziedzictwa kulturowego, mało znane, a przy tym dobrze zachowane w terenie. Kompleksy te po zagospodarowaniu mogą stanowić wybitnie cenne zasoby geoturystyczne województwa pomorskiego.Article is based on analysis of archival cartographic materials and Polish–German literature from the period between the 16th and 21th centuries. It presents the sites of old amber mines in the Pomerania Province. In total 32 new and unknown amber mines were found and the study of historical topographic maps made it possible to establish the very exact location of places mentioned in previous works. The analysis of historical materials conducted by the author points to locations of unknown, well-preserved, old extraction sites, which are valuable due to their cultural heritage. After some investment in the local infrastructure, the sites can make attractive spots in the region. The geosite of Bursztynowe Kule’ in Tricity Landscape Park is one of such places were well-preserved old amber mines are to be found. The final result of library research is the GIS ‘Digital map of former amber mines in the Pomerania Province’

Prussian geological maps of Northern Poland in the archives of the Polish Geological Institute and their current application in geology

The article characterizes first general geological (lithological-stratigraphical) maps presenting Quaternary deposits in Northern Poland. These were the maps of territory of the Prussian partition, elaborated by German geologists from Prussian Geological Survey “Königlich Preussische Geologische Landesanstalt”. After Poland regained its independence they became a basis for many Polish geological publications. The article discusses the chronology and objectives of the main cartographic works of German geologists operating in the area of present-day Northern Poland (general and detailed geological maps) and briefly presents the methodology of geological mapping of lowlands at the scale of 1:25,000

Mass-Movement Causes and Landslide Susceptibility in River Valleys of Lowland Areas: A Case Study in the Central Radunia Valley, Northern Poland

This work aims to analyse the mechanisms and factors contributing to shallow soil landslides in river valleys entrenched in lowlands on the example of the Central Radunia Valley. The combination of susceptibility analysis using geographic-information-system-based statistical models, field surveys, analysis of archival materials, and numerical modelling for the analysis of slope stability and hydrogeological processes allows for comprehensive landslide reconstruction, mass movement mechanism description, and an explanation of the role of triggering and causal factors. The results emphasise the need for cross-disciplinary studies of shallow soil landslides. The identification and prioritisation of the causal factors indicate that geomorphological conditions play a particularly important role. The current study shows that the greatest influence on landslide formation in the Central Radunia Valley is slope angle, as determined using a high-resolution digital elevation model. The slope angle factor is sufficient to produce a reliable susceptibility map (the areas under the curve of the success rate and prediction rate curves are 87.84% and 85.34%, respectively). However, numerical modelling of slope failure also clearly indicated that there was a significant influence of anthropogenic impacts on the landslide process. We determined that the main triggering factor causing the January 2019 Rutki landslide was related to the drilling of a borehole on 10 January 2019. The water used for drilling hydrated the soil and thus weakened the stability conditions