"Achieving international distinction for creativity, innovation and excellence in geographical, geological and environmental education, research and outreach."

Publications

Papers
Presentations (selected)
Conference Posters

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Papers

 

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Presentations (selected)

OPWALL International Graduate Science Talk – Hoga Island, Wakatobi, Indonesia, August 2012: The late Holocene flooding history of Runway Sinkhole: a partially flooded coastal karst basin in the northern Bahamas

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Conference Posters

 

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Teaching

McMaster University	EARTH SC/ENVIR SC 3QQ3, Introduction to Scientific Dating Methods	T.A.
McMaster University	EARTH/ENVIR SC 2E03 Earth History, 2012-13	T.A.
McMaster University	EARTH SC 4FF3,Topics of Field Research, 2012-13	F.A
McMaster University	EARTH SC 4E03, Coastal Environments, 2012-13	F.A
McMaster University	EARTH SC 2Q03 – Introduction to Geochemistry	U.A
McMaster University	EARTH SC 2GG3 – Natural Disasters	U.A
McMaster University	EARTH SC 1B03 – Environmental Systems	U.A
McMaster University	GEOG 1HA3 – Human Geography: Society & Culture	U.A

 

 

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Affiliations

 

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Research

Research Interests:

• Quaternary sea-level oscillations and climate variability
• Aquatic micropaleontology (foraminifera, thecamoebians)
• Coastal geology and catastrophic event stratigraphy (hurricanes, tsunamis)
• Karst hydrogeology
• Stable (standard, clumped) and radiogenic isotope geochemistry
• Coral physiology

Thesis Summary:

Coastal karst basins have a worldwide distribution, yet the geologic and environmental mechanisms operating on these systems over millennial timescales remains poorly understood. Coastal karst basins (CKBs) is a term that includes a variety of basin-like features formed on carbonate terrain from the long-term dissolution of carbonate landscapes (van Hengstum et al., 2011). These features include underwater caves, blueholes, and sinkholes, and they formed as a result of often- complex dissolution patterns and modification of limestone terrains over the Quaternary (Mylroie, 1984; Mylroie et al., 1995; Smart et al., 2006). After formation, however, CKBs provide accommodation space for sedimentation (e.g., Watts and Hansen, 1994; Gischler, 2003; Alverez, 2005; Yamamoto et al., 2010), and habitat for a variety of intrinsic aquatic and terrestrial ecosystems (Wilson and Humphreys, 2001; Martínez-García et al., 2009).

Previous evidence from speleothems indicates that sea level and groundwater oscillate in near synchrony on coastal carbonate terrain during glacioeustatic sea-level cycles (Gascoyne et al., 1979; Richards et al., 1994; Suric? et al. 2005). However, speleothems can only evidence the switch between the vadose versus phreatic state of a CKB in response to inundation of a carbonate platform by sea-level rise. As a result, the intrinsic environmental progression that occurs within CKBs during sea-level change has largely been a challenge to resolve with speleothems alone, despite abundant evidence that discrete environments develop in CKBs on modern coastlines. Over the last 30 years, ongoing research indicates that unique subterranean environments and ecosystems develop in CKBs with respect to sea level (e.g., Holthuis, 1973; Stock et al., 1986; Ginés and Ginés, 2007). van Hengstum and Scott (2011) refined the previous conceptual framework for the environments that occur in CKBs into a four-tiered system: vadose, littoral, anchialine, and submarine. Vadose environments occur above sea level or the groundwater table and in the vadose (unsaturated) zone. Littoral environments develop when sea level or a groundwater table is positioned predominantly within a CKB, giving rise to unique sedimentary and environmental processes. The conceptual framework for anchialine environments is more complex, including variable salinity and dissolved oxygen levels, broad subterranean connection with the ocean through the porous limestone bedrock, and although Stock et al. (1986) determined that they have both marine and terrestrial influences, van Hengstum and Scott (2011) proposed that anchialine environments are dominated by terrestrial influences to help differentiate anchialine versus submarine environments. This is in contrast to submarine environments, which are (i) completely flooded by seawater or saline groundwater, (ii) their physical conduit entrances (if present) open below sea level in the coastal zone, and (iii) they are dominated by marine influences. All of these subterranean environments can be observed along modern carbonate coastlines, but how these environments relate through geologic time and sea-level oscillations still remains controversial.

 

 

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Service

• Departmental Meeting Student Reps, 2012-13

 

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Updated January 16, 2013