ABSTRACT

Gravity surveys using relative gravity meters are often tied to accessible, accurate and stable gravity reference stations. Since 1947 gravity reference networks have included pendulum gravity stations, New Zealand Primary Gravity Network stations, stations at geodetic benchmarks, base stations established by GNS Science and absolute gravity stations (since 1995). New Zealand Gravity Reference Stations 2020 is a revision of earlier gravity networks and includes precise observations made with relative meters since the 1970s that for the first time are referenced to absolute gravity measured in New Zealand. Currently there are 1710 gravity reference sites with 1475 sites classed as usable. The gravity across the network has been combined in a set of least squares calculations with an estimated uncertainty for gravity at geodetic benchmarks and GNS Science base stations of ± 0.3 µN/kg, and ± 0.6 µN/kg at New Zealand Primary Gravity Network stations. Gravity stations affected by large earthquakes since 1990 have been resurveyed, and gravity changes due to long term variations in elevation, local fluctuations in groundwater level and alteration to nearby topography from erosion and roadworks are estimated at < ± 0.3 µN/kg.

摘要

使用相对重力仪进行的重力测量通常与可访问、准确和稳定的重力参考站相关联。自 1947 年以来，重力参考网络包括摆式重力站、新西兰初级重力网络站、大地测量基准站、GNS Science 建立的基站和绝对重力站（自 1995 年以来）。新西兰重力参考站 2020 是对早期重力网络的修订，包括自 1970 年代以来使用相对仪表进行的精确观测，首次参考在新西兰测量的绝对重力。目前有 1710 个重力参考站点，其中 1475 个站点被归类为可用站点。整个网络的重力已结合在一组最小二乘计算中，在大地基准和 GNS Science 基站的重力估计不确定性为 ± 0.3 µN/kg，在新西兰主要重力网络站为 ± 0.6 µN/kg。重新测量了自 1990 年以来受大地震影响的重力站，估计由于海拔长期变化、地下水位的局部波动以及侵蚀和道路工程对附近地形的改变导致的重力变化为 < ± 0.3 µN/kg。