Research

Islands of History

My research asks how, and why, people created new island societies. Two projects are active now; earlier projects, with links to coverage and key papers, follow.

Moai · Palau · Earlier projects

Active · Rapa Nui (Easter Island) · National Science Foundation, 2023–2026

Explaining the Destruction of Monumental Architecture

Why did people in the past destroy monumental architecture? Previous research has focused on how monuments were built, with far less attention to the cause, or causes, of their damage and demolition. That leaves us with a lopsided view of the past. On Rapa Nui, hundreds of massive statues (moai) that once stood on platforms now lie toppled. Many believe they were pulled down by people during a period of conflict; others have suggested neglect, or strong earthquakes.

The project has two aims. The first is to build a timeline of when statues fell by measuring how far their tuff, a stone made of compacted volcanic ash, has weathered since they hit the ground. We use ultrasound instruments originally developed by engineers to test concrete, which lets us take readings without damaging the stone, alongside controlled weathering experiments in the lab. The fieldwork is carried out with the Terevaka Archaeological Outreach program, which gives local high school students hands-on experience in conservation and research.

The second aim is to test the possible causes of toppling. Using archaeoseismology, computer simulations, and earthquake records specific to Rapa Nui, we model how a standing moai behaves in a strong earthquake and compare that with the physical evidence for deliberate destruction and neglect.

Active · Republic of Palau · Defense POW/MIA Accounting Agency

Search and Recovery in the Republic of Palau

Alongside my academic research, I lead an archaeological search and recovery effort for a U.S. Marine pilot who crashed in the Republic of Palau during World War II. The work is funded by the U.S. Department of Defense’s Defense POW/MIA Accounting Agency (DPAA) through its partnership program with universities, and brings the methods of archaeology, including survey, mapping, and controlled excavation, to the task of accounting for the missing.

The site is the wreckage of a Vought F4U-1D Corsair in Aimeliik State. The first field season, in 2023, was conducted in partnership with Southern Methodist University; a second season ran from June to August 2025 from Florida State, with Dr. Sayali Sangamnerkar as lead archaeologist.

Earlier projects

Completed projects, newest first. Each lists where the results were covered and the papers to start with; the full publication list has everything else.

2021–2025 · National Science Foundation · with Scott Ortman, Amy Bogaard, and Timothy Kohler

The Global Dynamics of Inequality (GINI)

How old is economic inequality, and what drives it? An international working group assembled a database of tens of thousands of house floorplans from archaeological sites around the world, spanning roughly twelve thousand years, on the principle that the size of a house tracks the wealth of the household that built it. The results were published as a set of papers in PNAS in 2025; the paper I led found that war both reduced and increased inequality, depending on the kind of society doing the fighting.

2019–2020 · NSF SPARC Research Collaboration Award · with Adam Johnson and Thegn Ladefoged

Royal centers in the early states of ancient Hawaiʻi

Drone-based lidar mapping of settlements along the Kona coast of Hawaiʻi Island, carried out with Kānaka Maoli stewards and Hawaiʻi State Parks, to ask what influence royal centers had on the wider settlement pattern beyond the boundaries of their sacred precincts.

2017–2021 · Royal Society of New Zealand Marsden Fund · with Thegn Ladefoged, Dion O’Neale, and Chris Stevenson

The Making of Māori Society

A major interdisciplinary project that used geochemical sourcing of obsidian artefacts to build computer models of ancient social networks among Māori, and asked how changes in those networks help explain the evolution of society in Aotearoa New Zealand before European contact.

2019–2022 · with Juliet Sefton, Andrew Kemp, and colleagues

Sea-level change and the settlement of Micronesia

Reconstructing relative sea-level history across Micronesia from mangrove sediments, and what an anomalous 5,700-year record implies about when people first reached, and could have lived on, the islands of Remote Oceania.

2017–2019 · National Center for Preservation Technology and Training · with K. Ann Horsburgh

Microbial impacts on archaeological collections

Testing how microbial communities affect the preservation of ancient DNA in archaeological animal bone held in museum collections, with the aim of improving how such collections are stored and sampled.

2017–2021 · book and methods papers

Maps for Time Travelers and the geospatial revolution

A run of work on what geospatial technology, from airborne lidar to big geospatial data, is doing to archaeology, written for colleagues in the journals and for everyone else in Maps for Time Travelers (University of California Press, 2020), which received the Society for American Archaeology’s Book Award in 2021.

2012–2013 · National Geographic Society

The origins of Nan Madol

Coral dating and geochemical sourcing of the megalithic architecture of Nan Madol on Pohnpei, Federated States of Micronesia. The work produced the earliest direct evidence for monument building at the site, around AD 1180, and with it evidence for the rise of the first chiefdom in the region.

2010–2013 · Royal Society of New Zealand Marsden Fund

The Archaeology of Territoriality

Trade, conflict, and agriculture in New Zealand before European contact, studied through where Māori communities obtained obsidian and how those supply zones shifted as territories formed.

2003–2022 · with Thegn Ladefoged, Michael Graves, Gregory Asner, and colleagues

Agricultural landscapes of Hawaiʻi Island

Airborne lidar survey and fine-grained dating of the Kohala and Kona field systems, the vast dryland farming landscapes that fed the Hawaiian chiefdoms, and what their development says about risk, innovation, and religious life in the fields.

2001–2008 · doctoral research, University of California, Berkeley · NSF Dissertation Improvement Grant

Kalaupapa, Molokaʻi

Three seasons of fieldwork on the Kalaupapa peninsula, reading five centuries of change in Hawaiian society, from AD 1250 to 1800, through the history of its communities, field systems, and shoreline.