USGS Global Fiducials Library: 1999-2009

A Fiducial site is a geographic location that is used as a benchmark for the long-term monitoring of processes, both natural and anthropogenic, associated with the causes and effects of global environmental change. The word fiducial carries multiple meanings with regard to the GFL. Fiducials are marks or points of reference applied to images to present a fixed standard of reference, so in the GFL they refer to the identification of a place on the Earth. The term fiducial may also be interpreted to refer to a long-term trust, where one may be holding something in trust for another. Both references aptly apply, as the GFL maintains a long-term record of data over specific places on the Earth to be available for scientific investigations. Fiducial sites are associated with Earth processes and environmentally sensitive areas that are being monitored so that scientists can better understand and model the dynamic systems and changes that are occurring. The sites are located around the globe and are distributed among environmental topics and processes within five major disciplines: Ocean Processes; Ice and Snow Dynamics; Atmospheric Processes; Land Use/Land Cover; and Geologic Processes.基准站点（Fiducial site）是指被用作长期监测各类自然与人为过程的地理参照点位，这些过程与全球环境变化的成因及影响密切相关。就GFL而言，“fiducial”一词具有多重内涵：其一，基准参照点（Fiducial）是指用于图像中以提供固定参照标准的标记或参照点位，因此在GFL中，该术语指代地球上特定地点的标识；其二，“基准”也可被理解为长期托管之意，即一方为另一方受托保管相关事物。这两层含义均贴切适用，因为GFL会对地球上特定地点的相关数据进行长期留存，以供科学研究使用。基准站点与正处于监测中的地球过程及环境敏感区域相关联，旨在助力科学家更深入地理解并建模当下正在发生的动态系统与变化。该类站点遍布全球，覆盖五大核心学科下的各类环境主题与研究过程：海洋过程、冰雪动力学、大气过程、土地利用/土地覆被以及地质过程。