Crowdsourcing historical photographs: autonomy and control at the Copenhagen City Archives

This study of crowdsourcing practices at Kbhbilleder.dk at the Copenhagen City Archives provides a rich description of how motivation and work relations are situated in a wider infrastructure of different tools and social settings. Approximately, 94% of the work is here done by 7 of the 2,433 participants. The article contributes insights into how these super-taggers carry out their work, describing and placing images on a map, through an extensive discursive effort that takes place outside the institution’s more limited interface in private discussion forums with over 60 000 participants. The more exploratory qualitative work that is going on in different discussion groups does not fit within the archive’s technical framework. Instead, alternative archives are growing within privately owned networks, where participants’ own collections merge with images from public archives. Rather than focusing on the nature of participants’ motivation, the article suggests a relational perspective on participation that is useful for analyzing a systems’ support for participation. Pointing out how people’s motivation in citizen science correspond with relational and intra-relational aspects enables an approach to system design that potentially supports or counteracts these aspects.

Atlantic Forest meeting Cerrado: floristic, structure, and species distribution of an ecotonal tree community

We evaluated the floristic and structural composition of a tree community in an ecotone between Cerrado (cerradão) and Atlantic Forest (seasonal semideciduous forest) domains located in Porto Ferreira State Park (PFSP), southeastern Brazil. We compared the floristic relationships of this ecotone with those of previous surveys carried out on the same vegetation types and checked the species distribution among the Brazilian biomes. We sampled all living trees with PBH>10 cm in 64 10x10 m plots (0.64 ha), totaling 1,755 individuals belonging to 101 species and 37 families. The richest families were Myrtaceae (13 spp.) and Fabaceae (11 spp.), and Siparuna guianensis was the most abundant species (188 individuals). We reported two threatened species. A great number of species are widely distributed, occurring in different Brazilian biomes. Floristic similarity values were low among the selected studies, but our sampled community clustered with communities of cerradão and ecotone areas of previous surveys. Our results corroborate that ecotonal areas have great tree diversity and the predominance of widely distributed species. This fact, combined with the vegetation thickening verified through historical photographs, reinforces that the study area belongs to an under-changing ecotone.

Mechanisms of Pond Expansion in a Rapidly Submerging Marsh

The development and expansion of ponds within otherwise vegetated coastal marshes is a primary driver of marsh loss throughout the world. Previous studies propose that large ponds expand through a wind wave-driven positive feedback, where pond edge erosion rates increase with pond size, whereas biochemical processes control the formation and expansion of smaller ponds. However, it remains unclear which mechanisms dominate at a given scale, and thus how, and how fast, ponds increase their size. Here, we use historical photographs and field measurements in a rapidly submerging microtidal marsh to quantify pond development and identify the processes involved. We find that as small ponds emerge on the marsh platform, they quickly coalesce and merge, increasing the number of larger ponds. Pond expansion rates are maximized for intermediate size ponds and decrease for larger ponds, where the contribution of wave-driven erosion is negligible. Vegetation biomass, soil shear strength, and porewater biogeochemical indices of marsh health are higher in marshes adjacent to stable ponds than in those adjacent to unstable ponds, suggesting that pond growth rates are negatively related to the health of the surrounding marsh. We find that the model of Vinent et al. (2021) correctly predicts measured pond growth rates and size distribution, which suggest the different mechanisms driving pond growth are a result of marsh drowning due to sea level rise (SLR) and can be estimated by simplified physical models. Finally, we show that all relevant processes increasing pond size can be summarized by an empirical power-law equation for pond growth which predicts the temporal change of the maximum pond size as a lower bound for the total pond area in the system. This gives a timescale for the growth of ponds by merging and thus the critical time window for interventions to prevent the irreversible pond expansion associated with large scale pond merging.

Preserving Holocaust History: Geophysical Investigations at the Ponary (Paneriai) Extermination Site

Holocaust mass grave sites in eastern Europe can be difficult to investigate due to a paucity of historical documentation relating to the events and because using traditional invasive archaeology methods raises concerns around the disturbance of the remains of Jewish people. When combined with other lines of evidence, including historic photos and eyewitness testimony, non-invasive geophysical methods help to effectively identify and demarcate buried features at Holocaust sites, limiting unnecessary excavations. Between 1941 and 1944, as many as 100,000 people were murdered at the Ponary (Paneriai) extermination site in Lithuania, but many critical details of the site layout during this period are still to be resolved, including the location of some of the mass graves and confirmation of an escape tunnel that was used by slave labourers to escape captivity and certain death at the site. In this study, we show how a combination of electrical resistivity tomography (ERT) profiling, limited ground-penetrating radar (GPR) data, and bare-earth elevation data (from a light and distance ranging (LiDAR) dataset) were used to confirm the location of a large unmarked mass grave with a diameter of ~25 metres and depth of ~4 metres. Additional ERT profiling at a second location imaged the entrance to an escape tunnel previously uncovered by an archaeological excavation in 2004, and detected a ~5 metre section of the continuation of the tunnel, approximately 33 metres away from the tunnel entrance. The geophysical results are supported by evidence from limited archaeological excavations, historical photographs, eyewitness descriptions of the site layout, and testimonies from the few survivors who managed to escape Ponary.

WHERE ARE WE NOW ON THE ROAD TO 4D URBAN HISTORY RESEARCH AND DISCOVERY?

From 2016 to 2021 the research group HistStadt4D investigated and developed methods and technologies to transfer extensive repositories of historical photographs and their contextual information into a 3D spatial model, with an additional temporal component. The aim was to make content accessible to researchers and the public, via a 4D browser and location-dependent augmented reality representation. Against this background, in this article we present the achievements of the project, lessons learned, and current state of 4D urban history research and discovery based on historical photographs.

Ireneusz Wierzejewski: treatment of amputees of the upper limb in Poznan during the Great War

Introduction The Great War (1914–1918) caused a dramatic increase in the number of limbless invalids. Orthopaedics became the field of medicine that could offer the most effective help for those patients. Objective This review article aims to present how new operations and methods in the field of orthopaedics spread to other countries during the Great War. Methods Historical photographs of patients treated by being given hand prostheses are analysed and discussed as a case study of the transfer of orthopaedic techniques in Europe. The pictures were taken in a provincial military hospital, directed by Ireneusz Wierzejewski, the pioneer of orthopaedics in Poland. Results The methods of preparing stumps for prostheses at Wierzejewski’s hospital followed the patterns of the time. In some cases, the prostheses were further modified to better help patients return to their former lives. Conclusion The case of the Fortress Hospital in Poznań demonstrates that kinetic hand prostheses were also available in provincial hospitals. Modern orthopaedic procedures remain an effective treatment and a way to restore amputees to society.

DATA FUSION OF HISTORICAL PHOTOGRAPHS WITH MODERN 3D DATA FOR AN ARCHAEOLOGICAL EXCAVATION – CONCEPT AND FIRST RESULTS

Through the destruction of war, most of the documents of an archaeological excavation from 1934 – 1939 of a megalithic tomb in north-west Germany have been destroyed irretrievably. Fortunately, more than 500 historical pictures have been preserved, which visually document the excavation situation at that time. Parts of the image collection are preserved on fragile glass plates that are difficult to preserve and have to be digitised urgendly. A method for digitising these glass plates will be presented first. With the help of the digitised historical images, the excavation situation at that time shall be reconstructed. Since a reconstruction based only on the historical images is not possible, the current state of the megalithic tombs has been recorded with modern measuring technology and a 3D model has been calculated. The aim is to fuse the historical images with the modern 3D model. For this purpose, different possibilities of linking the data are presented. As first results, point clouds calculated by Structure from Motion and the orientation of historical images in relation to the modern 3D model using direct linear transformation are shown. The hybrid model of historical and modern data will be used for archaeological interpretations of the excavation.