Hosts of the November 9, 2021, Darcy lecture made this graph of attendance. A total of 362 people attended that seminar. The seminar was organized by the Great Britain Chapter of International Association of Hydrogeologists (IAH), the Hydro group of the Geological Society (of London), IAH Western & Central European Chapter.

The virtual format made the Darcy lectures reach further than they normally would. In the UK, the Universities of Cambridge, Oxford, and St. Andrews organized a colloquium consortium called Earth to Earth. The USGS offices have nationwide Water Mission Area monthly talks. The EPA’s Office of Research & Development organized a Darcy lecture that was open to all its divisions. The Deutsch IAH and German Federation of Groundwater organized a Germany-wide seminar series. Since the pandemic prevented international travel, we arranged three broadcasts in November 2021 and three more in March 2022 to reach places as diverse as Australia, Chile, Colombia, New Zealand, France, Israel, Estonia, Ethiopia, Indonesia, Turkey, The Philippines, Spain, South Africa, Slovakia, Peru, Nigeria, Mongolia, Mexico, The Netherlands, and Brunei Darussalam.

Further, everyone wanted to ask the Darcy lecturer, “What are the research trends in groundwater sciences learned from these trips and conversations?” I spotted two: climate change mitigation and machine learning.