Geophysical Methods, Principles, and Results
Introduction
Sub-surface geophysical survey methods and 3D laser scanning of existing environments provide cost-effective means for capturing archaeological information for site recording, investigation, and management. Using non-invasive sub-surface and surface mapping methods can document the basic structure and layout of site. These methods can guide placement of excavation units and contribute to site impact strategies when dealing with upgrade of site infrastructure (such as utilities and landscape management); thus providing cost savings while reducing destructive impact upon important archaeological remains.
These non-invasive survey methods can provide primary information on site settlement patterns. The continued application and development of broad area coverage for archaeological assessment has begun to introduce an alternative perspective into regional, or landscape. Because geophysical surveys are able to cover large areas in comparison to the limited extent of archaeological excavations, the information they provide introduces a new component to the concept of the archaeological landscape. Broad area geophysical surveys provide information on the structure and organization of a site enabling the study of spatial patterns and relationships relevant to research questions. In addition to the large-scale perspective of the site, geophysical survey results also provide a high-resolution focus on individual site features.
Sub-surface geophysical survey methods and 3D laser scanning of existing environments provide cost-effective means for capturing archaeological information for site recording, investigation, and management. Using non-invasive sub-surface and surface mapping methods can document the basic structure and layout of site. These methods can guide placement of excavation units and contribute to site impact strategies when dealing with upgrade of site infrastructure (such as utilities and landscape management); thus providing cost savings while reducing destructive impact upon important archaeological remains.
These non-invasive survey methods can provide primary information on site settlement patterns. The continued application and development of broad area coverage for archaeological assessment has begun to introduce an alternative perspective into regional, or landscape. Because geophysical surveys are able to cover large areas in comparison to the limited extent of archaeological excavations, the information they provide introduces a new component to the concept of the archaeological landscape. Broad area geophysical surveys provide information on the structure and organization of a site enabling the study of spatial patterns and relationships relevant to research questions. In addition to the large-scale perspective of the site, geophysical survey results also provide a high-resolution focus on individual site features.
Geophysical surveys measure different subsurface properties at regular intervals across broad areas. Contrasting properties in a relatively homogeneous soil can identify buried objects or features such as foundations, compacted earthen surfaces, pits, stone walls, middens, hearths and any number of archaeological features. The different physical properties of the features, measured either in contrast to their surrounding matrix, or as recorded at the surface are referred to as ‘anomalies’ until they are able to be ground-truthed through excavation or other methods such as soil coring.
Different geophysical methods are sensitive to specific properties, such as magnetic fields, or the flow of an electrical current in the earth. Employing a combination of methods over a survey area can help provide information as to the nature, or material, of an anomaly thus providing insight to site interpretation. Mapping the distribution of anomalies over a large area can help in the recognition of anomalies generated through cultural activities revealing the spatial distribution and association with site features.
Geophysical surveys can provide important information for help in site planning and preservation. These non-invasive methods can help establish priorities and identify areas for further invasive investigations, or for preservation and management. They are a fast and cost-effective method for gaining insight to what is buried beneath the ground. Geophysical survey results can be spatially integrated with other data relevant to archaeological investigations to provide a comprehensive record of the site environment, both below, and above ground.
Geophysical surveys can provide important information for help in site planning and preservation. These non-invasive methods can help establish priorities and identify areas for further invasive investigations, or for preservation and management. They are a fast and cost-effective method for gaining insight to what is buried beneath the ground. Geophysical survey results can be spatially integrated with other data relevant to archaeological investigations to provide a comprehensive record of the site environment, both below, and above ground.