AAPG

Organization Structure and Leadership

Guided by science. Strengthened by leadership.

AAPG leadership consists of three governing bodies: the Executive Committee, the Advisory Council, and the House of Delegates. Members of all three bodies are elected, non-staff officials.

The Executive Committee guides AAPG’s overall mission, vision, and direction. The Advisory Council reports to the Executive Committee and conducts strategic planning and advises on questions around the constitution and bylaws, awards and honors nominees, and AAPG’s structure.

The House of Delegates is responsible for AAPG’s legislative functions and is made up of delegates from affiliated societies and international regions. Additionally, AAPG’s staff is made up of 40+ full-time employees across three offices. Staff are led by AAPG’s executive director and supported by hundreds of volunteers.

AAPG Leadership

AAPG’s Executive Committee is comprised of leaders elected by voting Members of the Association. It exercises executive control and management of AAPG’s affairs and funds. The Executive Committee serves as the Association's board of directors and consists of the following members (followed by term): President (one year), President-Elect (one year), Vice President, Sections (two years), Vice President, Regions (two years), Secretary (two years), Treasurer (two years), Editor (three years), Chair, House of Delegates (one year).

Brian Horn

President 2025 - 2026

John Casiano

President Elect 2025 - 2026

Maria Mutti

Regions Vice President 2025 - 2027

Lorena Moscardelli

Sections Vice President 2024 - 2026

Andrea Reynolds

Secretary 2025 - 2027

Daniel Minisini

Editor 2025 - 2028

Rebecca Caldwell

Treasurer 2024 - 2026

David Hawk

Chair House of Delegates 2025 - 2026

Thomas Wilker

Executive Director

Tom Wilker

Executive Director

[email protected]

The executive director is the chief operational leader of the AAPG. Thomas Wilker began serving as executive director in May 2025.

Prior to joining AAPG, Wilker had an impressive career in the private sector, including former leadership roles at Devon Energy, Burlington Resources, The Carlyle Group, and EP Energy. Most recently, he was the chief operating officer for PetroSkills, where he successfully led operations and contributed to the company’s continued growth. Before joining PetroSkills, Wilker served as senior vice president, subsurface at Wood Mackenzie. There, he oversaw several product lines and directed more than 70 subject matter expert employees comprised of geologists, engineers, GIS professionals, technical sales personnel, product managers, and data scientists.

Wilker is also the president and founder of his own energy consultancy, Curator Upstream, based in The Woodlands, Texas and is a Texas State Licensed Geophysicist.

AAPG’s House of Delegates is made up of representatives from affiliated societies and international regions throughout the world. They are selected by popular vote from within their respective regions and serve a three-year term.

HoD leaders disseminate information from AAPG to their respective society or region and assist in recruiting prospective AAPG members. The HoD is led by three officers.

David Hawk

Chair

Consultant

2025 - 2026

Energy Analysis and Answers

Chad Cummings

Chair Elect

Petroleum Geologist

2025 - 2026

Gunn Oil Company

Stephen Ladner

Secretary Editor

Consultant

2025 - 2026

Ladner Consulting

Learn More

The Advisory Council serves in an advisory capacity to the Executive Committee. They report on matters involving ethics and discipline, long-range planning, constitutional review, nominations for officers and honors and awards and other special projects as requested by the Executive Committee.

Members of this committee serve three years and include the immediate past-president and two former presidents, the immediate past chairman of the House of Delegates, elected members from the AAPG's U.S. Sections and International Regions, officers of each Division.

Claudia Hackbarth

Past President

2025 - 2026

Staff Liaison

Governance & Executive Operations Lead

2016 - 2099

AAPG Sections and Regions

United States Sections

AAPG sections are domestic groups of individuals and affiliated geological societies. They hold events and technical meetings locally—a great way to network with other AAPG members nearby.

International Regions

AAPG regions are international groups of individuals and affiliated geological societies. Each region organizes networking and thought leadership events for current and prospective members.

AAPG Committees

AAPG committees are smaller governing bodies that advise and guide various programs, research, and organization initiatives. They are comprised of subject matter experts.

Astrogeology
Corporate Advisory Board
Distinguished Lecture
Research
Student Chapters
Imperial Barrel Award

AAPG Committees

AAPG Divisions

AAPG divisions are member-only groups within AAPG that advocate for and disseminate information related to professional standards or technical geoscience subjects.

Division of Professional Affairs

The Division of Professional Affairs (DPA) is the largest division within AAPG. Their purpose is to promote professionalism and ethical standards, assist in career planning and education, and improve the overall success of AAPG members. The DPA also serves as the Board to become a Certified Petroleum Geologist, Petroleum Geophysicist, or Coal Geologist.

Learn more about the DPA

Energy Minerals Division

The Energy Minerals Division (EMD) is committed to advocating for, providing technical information, and assisting in educational and training events for energy professionals working with unconventional and alternative resources. The EMD contains energy resource-related committees, including geothermal, critical minerals, uranium, coal, helium, hydrogen, and more.

Learn more about the EMD

Division of Environmental Geosciences

The Division of Environmental Geosciences (DEG) promotes awareness and education of the environmental effects of exploration and development of conventional, unconventional, and alternative energy resources. The DEG organizes and hosts webinars, workshops, and small conferences on topics that range from managing orphan, abandoned, idle and marginal wells, to determining how to repurpose old wells, and to work with produced water.

Learn more about the DEG

Petroleum Structures and Geomechanics Division

The Petroleum Structures and Geomechanics Division is comprised of members that work in and are interested in the discipline of geomechanics and petroleum structural geology. They conduct field trips, webinars, and meetings with a focus on relating structure and geomechanics to subsurface energy exploration and development.

Learn more about the PSGD