Moai

Explanation and conservation in archaeology require detailed representations of the archaeological record. For conservation purposes, our goal is to document the current configuration of the record with as much detail as possible. For archaeological analysis, ABSTRACT Structure from motion (SfM) mapping is a photogrammetric technique that offers a cost-effective means of creating three-dimensional (3-D) visual representations from overlapping digital photographs. The technique is now used more frequently to document the archaeological record. We demonstrate the utility of SfM by studying red scoria bodies known as pukao from Rapa Nui (Easter Island, Chile). We created 3-D images of 50 pukao that once adorned the massive statues (moai) of Rapa Nui and compare them to 13 additional pukao located in Puna Pau, the island's red scoria pukao quarry. Through SfM, we demonstrate that the majority of these bodies have petroglyphs and other surface features that are relevant to archaeological explanation and are currently at risk of continued degradation. El mapeo de estructura a partir del movimiento (SfM por sus siglas en inglés) es una técnica fotométrica de bajo costo que permite crear representaciones visuales en tres dimensiones a través de la superposición de fotografías digitales. Actualmente la técnica es usada con más frecuencia para el registro de datos arqueológicos. Aquí demostramos la utilidad de la técnica SfM para estudiar los elementos esculpidos de escoria roja conocidos como pukao de Rapa Nui (Isla de Pascua, Chile). Se crearon imágenes en 3D de 50 pukao que alguna vez decoraron las enormes estatuas (moai) de Rapa Nui y se compararon con 13 pukao adicionales localizados en Puna Pau, la cantera en la isla donde se extraía la escoria roja utilizada para los pukao. A través del uso de la técnica SfM se demuestra que la mayoría de estos elementos tiene petroglifos y otros rasgos superficiales que son relevantes para las explicaciones arqueológicas y que actualmente se encuentran en riesgo de degradación continuada. we often seek to generate accurate descriptions of artifacts that include measures of shape and a record of physical attributes. Structure from motion (SfM) mapping offers a cost-effective method of achieving these goals by extracting three-dimensional data

Rapa Nui (Easter Island, Chile) presents a quintessential case where the tempo of investment in monumentality is central to debates regarding societal collapse, with the common narrative positing that statue platform (ahu) construction ceased sometime around AD 1600 following an ecological, cultural, and demographic catastrophe. This narrative remains especially popular in fields outside archaeology that treat collapse as historical fact and use Rapa Nui as a model for collapse more generally. Resolving the tempo of "collapse" events, however, is often fraught with ambiguity given a lack of formal modeling, uncritical use of radiocarbon estimates, and inattention to information embedded in stratigraphic features. Here, we use a Bayesian model-based approach to examine the tempo of events associated with arguments about collapse on Rapa Nui. We integrate radiocarbon dates, relative architectural stratigraphy, and ethnohistoric accounts to quantify the onset, rate, and end of monument construction as a means of testing the collapse hypothesis. We demonstrate that ahu construction began soon after colonization and increased rapidly, sometime between the early-14th and mid-15th centuries AD, with a steady rate of construction events that continued beyond European contact in 1722. Our results demonstrate a lack of evidence for a pre-contact 'collapse' and instead offer strong support for a new emerging model of resilient communities that continued their long-term traditions despite the impacts of European arrival. Meth-odologically, our model-based approach to testing hypotheses regarding the chronology of collapse can be extended to other case studies around the world where similar debates remain difficult to resolve.

A digital survey, combining photogrammetry and reflectance transformation imaging (RTI), offers significant new insights into the British Museum's Easter Island statue called Hoa Hakananai'a. These include the likelihood that it was made with a tapering base to stand in the ground, as seen by the crew of HMS Topaze in 1868, and that a nearby stone described a century ago was a pukau, a stone ‘hat’. Petroglyphs consisting of two komari (stylised female genitalia) were subsequently added. Succeeding these were bas-relief carvings, here interpreted as a single composition that narrates the island's birdman myth as recorded in the nineteenth and early twentieth centuries. This reading is supported by photographs of Hoa Hakananai'a taken in Chile in 1868. A new model is presented for the relationship between the statue and the birdman cult. As it now stands, in a nineteenth-century plinth, Hoa Hakananai'a appears to lean slightly from its intended placing.Eine Digitaluntersuchung, bei der Photogrammetrie und Reflectance Transformation Imaging (RTI) kombiniert wurden, bietet bedeutende neue Einblicke in die Osterinsel-Statue des British Museums, Hoa Hakananai'a genannt. So u.a., dass sie wahrscheinlich ursprünglich mit einem zugespitzten Sockel im Boden stand, wie dies von der Mannschaft des Schiffs Topaze im Jahre 1868 bezeugt wurde, und dass es sich bei dem vor einem Jahrhundert beschriebenen nahegelegenen Stein um einen pukau, einen steineren “Hut” handelte. Petroglyphen bestehend aus zwei komari (stilisierten weiblichen Genitalien) wurden nachträglich angebracht. Später folgten Basreliefs, die hier als eine alleinstehende Komposition interpretiert werden, die den im 19. und frühen 20. Jahrhundert aufgezeichneten Mythos des Vogelmannes zum Thema hat. Unterstützt wird diese Interpretation durch Photographien des Hoa Hakananai'a, die 1868 in Chile aufgenommen wurden. Ein neues Modell wird für die Beziehung zwischen der Statue und dem Vogelmann-Kult präsentiert. So, wie die Statue jetzt auf ihrem Sockel aus dem 19. Jahrhundert steht, scheint sich Hoa Hakananai'a leicht von dem für ihn ursprünglich beabsichtigten Standplatz wegzuneigen.

Explaining the processes underlying the emergence of monument construction is a major theme in contemporary anthropological archaeology, and recent studies have employed spatially-explicit modeling to explain these patterns. Rapa Nui (Easter Island, Chile) is famous for its elaborate ritual architecture, particularly numerous monumental platforms (ahu) and statuary (moai). To date, however, we lack explicit modeling to explain spatial and temporal aspects of monument construction. Here, we use spatially-explicit point-process modeling to explore the potential relations between ahu construction locations and subsis- tence resources, namely, rock mulch agricultural gardens, marine resources, and freshwa- ter sources—the three most critical resources on Rapa Nui. Through these analyses, we demonstrate the central importance of coastal freshwater seeps for precontact populations. Our results suggest that ahu locations are most parsimoniously explained by distance from freshwater sources, in particular coastal seeps, with important implications for community formation and inter-community competition in precontact times.

The archaeological record of Rapa Nui (Easter Island, Chile) is noteworthy for its massive statues (moai) that were transported over long distances with relatively small numbers of people and minimal use of resources. Equally impressive are the colossal bodies of red scoria (pukao) placed on the heads of many of the moai. In this study, we use three-dimensional models of 50 pukao found across the island and 13 red scoria cylinders from Puna Pau, the island's pukao quarry, to study the process of pukao manufacture, transport, and placement atop statues. Our analysis identifies surface features that are explained by the process of construction and transport of these multi-ton objects. Based on shared physical features of pukao, evidence in the archaeological record, and the physics necessary for pukao movement, we propose a falsifiable hypothesis in which relatively small numbers of people rolled pukao up stone ramps to place pukao atop moai. We conclude that activities of pukao production and transport did not require oversight by a centralized political authority, nor do they support notions of a large population that collapsed with " ecological suicide " on Rapa Nui.