GSA began with 100 members under its first president, James Hall. In 1889 Mary Emilie Holmes became its first female member.[3] It grew slowly but steadily to 600 members until 1931, when a nearly $4 million endowment from 1930 president R. A. F. Penrose Jr. jumpstarted GSA's growth. As of December 2017, GSA had more than 25,000 members in over 100 countries.
The society has six regional sections in North America, three interdisciplinary interest groups, and eighteen specialty divisions.[4]
The stated mission of GSA is "to advance geoscience research and discovery, service to society, stewardship of Earth, and the geosciences profession". Its main activities are sponsoring scientific meetings and publishing scientific literature, particularly the peer-reviewed journals Geological Society of America Bulletin, published continuously since 1889, and Geology, published since 1973. In 2005, GSA introduced its online-only journal Geosphere, and in February 2009, GSA began publishing Lithosphere (both also peer-reviewed). Geosphere and Lithosphere are open access as of 2018. GSA's monthly news and science magazine, GSA Today,[5] is also open access online. GSA also publishes three book series: Special Papers, Memoirs, and Field Guides.[6] A third major activity is awarding research grants to graduate students.[7]
GSA issues Position Statements "in support of and consistent with the GSA's Vision and Mission to develop consensus on significant professional, technical, and societal issues of relevance to the geosciences community. Position Statements, developed and adopted through a well-defined process, provide the basis for statements made on behalf of the GSA before government bodies and agencies and communicated to the media and the general public."[8]
For example, in 2006, the GSA adopted a Position Statement on Global Climate Change:
The Geological Society of America (GSA) supports the scientific conclusions that Earth's climate is changing; the climate changes are due in part to human activities; and the probable consequences of the climate changes will be significant and blind to geopolitical boundaries. Furthermore, the potential implications of global climate change and the time scale over which such changes will likely occur require active, effective, long-term planning.