NGS Webinar

On the Trail of the Changing Alaskan Geoid: Results of the 2025 Geoid Monitoring Survey

April 30, 2026 | 2:00–3:00 pm, ET

Presenters: 

Ryan Hardy, PhD, Geodesist and Geoid Modeler, NGS Gravity and Heights Branch;

Kevin Jordan, Cartographer, NGS Field Operations Branch

Webinar Description:

In the fall of 2025, NGS followed up the 2021 geoid monitoring field campaign to measure geoid change in southcentral Alaska’s rugged valleys. In this webinar, NGS presenters Ryan Hardy and Kevin Jordan will discuss the challenging gravity, GNSS, and astronomical observations required to create a high-resolution snapshot of how the gravity and heights change over time. This survey has mapped out the accuracy of GEOID2022 in this region and revealed accumulated changes in orthometric heights since the Coast & Geodetic Survey’s high-precision survey following the 1964 earthquake. The data from this campaign will be used to improve the spatial resolution of GEOID2022’s dynamic component.

*Technical Content Rating: Intermediate - Some prior knowledge of the topic is helpful.