Well-developed simple, stabilized parabolic dunes that are oriented to the east and southeast form the inland portion of a dune complex that extends ~32 km east-west across the southern shoreline of Lake Michigan in northwest Indiana. To better understand shoreline evolution during the Nipissing and post-Nipissing phases of Lake Michigan, subsurface sedimentology and radiocarbon ages from interdunal wetlands are considered with optical ages from nearby dunes within the landward portion of this area known as the Tolleston Beach. In the east, the once expansive Great Marsh had developed during the lake-level fall from the Nipissing peak (~4500 years ago). Units of eolian sand found within vibracores from the Great Marsh indicate that dunes formed and began migrating into the wetlands 4200–4400 years ago. In the west, newly formed dunes migrated along the shoreline while small interdunal wetlands formed shortly thereafter. Optical ages from two individual dunes indicate that this relict dune system stabilized by ~3500 years ago. Six samples collected from each of the two dunes yield optical ages that overlap at two standard errors. However, variations in individual ages detect episodic processes of sand movement that distinguish between the timing of landform migration and stabilization. Optical ages collected at the base of the slipface are interpreted as the age of landform stabilization. This study indicates that, with focused field-to-lab strategies, optical dating can provide a more robust chronology of shoreline development than previously considered; correlating eolian activity to wetland development and lake-level change in the Great Lakes.

The youngest dune belt along Lake Michigan's southern coast evolved through four stages. The first stage began during the Nipissing transgression, ~6.0 ka, and culminated at the Nipissing high, ~4.5 ka. Rising lake levels eroded the lake margins and generated sediment that was transported to southern Lake Michigan, creating the Tolleston barrier beach. The second stage, beginning ~4.5 ka with a rapid lake level fall and continuing to ~3.0 ka, represents a major episode of transgressive parabolic dune field development. Large, simple parabolic dunes, with easterly apices (85–105° azimuth) suggestive of westerly wind formation, developed in a sand belt ~1–2 km wide. The third stage, from ~3.0 to 1.0 ka, was characterized by strandplain progradation and transverse ridge development west of Miller, Indiana, and dune stabilization creating the Holland Paleosol east of Miller. Sporadic blowout activity from strong westerly winds redistributed the sand within the dune field, amalgamating simple dune forms into compound, rake-like, and nested parabolic dunes. The fourth and youngest stage, beginning ~1.0 ka, represents blowout development in a southeasterly direction (120–135° azimuth), indicating a wind direction shift to the northwest. Blowouts, whether developed in transverse ridges or in the northern arms of parabolic dunes, occur closest to the lake. The timing of this blowout initiation coincides with a rise in the level of Lake Michigan. However, a more likely development and maintenance mechanism for these dunes is increased storminess with strong northerly and northwesterly winds during the cooler months of the year.

This study focuses on the geomorphology and geochronology of dunes formed on three sandy barrier systems at Clark, Europe and Kangaroo Lakes in Wisconsin's Door Peninsula. The Lake Michigan shoreline in the peninsula contains abundant evidence for fluctuations in lake level with paleo-shoreline features that lie up to ~7 m above the present shoreline. Dunes are not very common along the Lake Michigan shoreline in Wisconsin, but the three bay barriers studied contain beach ridges that were buried by varying depths of eolian sand in the form of low relief sandsheets as well as parabolic and transverse dunes that have relief of up to 21 m. The purpose of this study was to document when the barriers formed and when the subsequent eolian activity occurred. The chronology presented here for barrier emplacement and dune development is based on 65 optically stimulated luminescence (OSL) samples which were collected from littoral sediment in the barriers (n = 17) and the overlying eolian sand (n = 48). Sediment samples were collected using bucket augers or a vibracoring device at depths ranging from 0.5 to 4.1 m below the ground surface. The OSL ages show that barriers in each of the study sites were constructed between ~5.9 and 3.9 ka, corresponding closely to the Nipissing high lake phase. OSL ages falling between 3.3 and 2.5 ka at the Kangaroo Lake site suggest the portion of the barrier closest to Lake Michigan formed during the Algoma phase. The majority of the eolian ages fall into two primary groups that overlap with or are slightly younger than the ages acquired from the barriers. These results suggest eolian activity ended between 4.5 and 3.7 (n = 20 ages) and 2.5 and 1.8 (n = 11 ages) ka. Both geomorphic and geochronological evidence suggests that dune development occurred rapidly when sand supply increased as lake levels fell following these two transgressive events.

Accurately reconstructing the rate of movement and extent of eolian dunes over thousands of years is a challenging endeavor. In this paper, we refine the methodology for utilizing lakes and bogs downwind of dune fields as precise recorders of past eolian activity. Sediment cores from two Allegan County lakes and one bog associated with dunes were studied to evaluate the importance of the various sand transport pathways into lakes and bogs. Goshorn Lake's western edge directly abuts a large parabolic dune. Sand concentrations decrease in cores away from the dunes, possibly reflecting avalanching into the lake followed by sediment gravity flows along the lake bottom. Sand input from stream flow was minor. The Allegan Bog core records a fen-emergent bog transition coincident with a decrease in the sand influx. Poorly understood shoreline processes may have contributed sand to the basin's center before the bog's emergence. Sand in Gilligan Lake cores is texturally similar to adjacent dune sand and the eolian activity history derived from this sand is nearly identical to the history derived from the dune's paleosols and optically stimulated luminescence ages. A proposed lake and bog sampling strategy includes choosing sites in the lee of large dunes edged with emergent vegetation and away from steep slopes or stream inlets. The lake's bathymetry should also be considered. Distinguishing between grain fall sedimentary structures and mass movement or sediment gravity flows is important. This strategy provides relatively high resolution, continuous eolian activity histories that can be correlated with paleoenvironmental proxies from the same cores.

Eolian sand deposited in lakes downwind of coastal sand dunes can record a history of paleoclimatic fluctuations. The eolian sand signals from sediment within the Grand Mere Lakes, Michigan, which are downwind of sand dunes along southeastern coastal Lake Michigan, record the same sunspot, climate history, and lake-level fluctuations observed elsewhere along the east-central Lake Michigan coastline. Sediment cores were extracted from the Grand Mere Lakes in Berrien County, Michigan, and analyzed for variations in weight percentage of sand with depth, the sand signal, at 1 cm sampling intervals. Radiocarbon dates obtained from terrestrial macrofossils within the cores were used to develop age-depth models, from which sedimentation rates were derived, both for the varying sedimentary facies and the entire core. Spectral analyses of the sand signal data using both multi-taper and REDFIT methods indicate multiple periodicities that correspond to those from other regional and global studies, including Lake Michigan lake-level fluctuations, Lake Michigan coastal dune formation, and solar cycles. The common periodicities between the Grand Mere Lakes sand data and other studies suggest the sand-signal data set is not random, and is best explained as a record of paleo dune mobility. The appearance of the 80–110 year Gleissberg solar cycle in the data suggests that the storminess recorded by the eolian sand was influenced by periodic variability in extratropical cyclones across the Lake Michigan basin which, in turn, reflects variability in circulation patterns driven by the North Atlantic Oscillation, the variability of which has been associated with solar cycles.

Interrelationships among late Holocene climate, the dynamics of coastal dunes and sedimentation in adjacent small lakes along coasts of the upper Great Lakes have been studied for over a decade. Nonetheless, many questions remain as to relationships between climate variability and dune activity. The study site is Oxbow Lake, near Saugatuck, Michigan, which formed as an artificial cutoff of the Kalamazoo River in 1906. Stratigraphic control of the infilled western end of the lake is from ground penetrating radar, and lake sediment from Livingstone and Glew cores with age control from 210 Pb/ 137 Cs/ 7 Be analysis. The climate data used included Lake Michigan water levels and temperature, precipitation, drought and evaporation data from a weather station 30 km to the south and wind data from buoys on Lake Michigan. Episodic peaks of eolian sand in the lake sediment are interpreted to be sourced from adjacent small parabolic dunes along the shoreline and from a foredune west of the lake. Linear regressions of the climate data and weight percent sand resulted in a variety of correlations, some conflicting, and with uncertain meanings. It was found through visual correlation that peaks in sand correspond with both peaks in water levels of Lake Michigan and the winter Palmer drought severity index. The implications of this research are that dune activity is linked to periods of wet conditions and storminess, contrary to typical eolian environments, but consistent with other studies in temperate coastal dunes along the Great Lakes. Results can be used as a modern analogue for coastal dune activity during times of high lake level.

This study investigates the impacts of extratropical cyclones on Lake Michigan dune complexes by integrating field measurements and meteorological data from sites along the southeastern shore. Surface changes and wind velocities were monitored at Hoffmaster State Park, Saugatuck Harbor Natural Area, and Mount Baldy at Indiana Dunes National Lakeshore from October to April in 2010–2011 and 2011–2012. Over 70% of the events with wind speeds at least two standard deviations above the mean were associated with extratropical cyclones. The wind directions depended on the cyclone path, with westerly or southerly components most common. Local conditions moderated the effects of storm winds on surface change. The greatest surface changes measured in a trough blowout at Saugatuck Harbor Natural Area were associated with regional winds with a component blowing up the lee slope that produced bifurcated windflow within the trough. While the orientation of a given dune strongly influences the amount of surface change, it does not always follow a simple pattern deduced from dune geometry. Surface changes at Hoffmaster State Park and Saugatuck Harbor Natural Area during a normal winter (2010–2011) and an unusually warm winter (2011–2012) suggest that colder weather conditions inhibited net transfer of sand from the beach but had less impact away from the shore. Moisture also inhibited sand transport, but strong storm winds moved wet sand, sometimes over long distances at Indiana Dunes National Lakeshore. Overall our results show that winds associated with extratropical cyclones play a vital role in the development of Lake Michigan dune complexes.

The evolution of Great Lakes coastal dunes includes long-term trends and short-term variations. This study explores multi-year, interannual and seasonal patterns of change as a Lake Michigan foredune responds to variations in lake level, weather and surface conditions. The study site is an active foredune in P.J. Hoffmaster State Park on the east coast of Lake Michigan. Foredune changes, local conditions and processes were monitored from 2000 to 2012 with repeated ground surveys, erosion pins, microclimate measurements, and observations of surface conditions. Additional weather and lake-level data were obtained from regional sources. Study results show a trend of foredune growth during the multiyear study period, with interannual and seasonal variations in the rates and spatial patterns of dune growth. At the scales of investigation, relationships between dune change and variables could not be quantified, but patterns of foredune change and influential variables were identified. The greatest amounts of erosion and deposition took place during the autumn and winter when strong winds were the most frequent, but storm conditions, vegetation changes, precipitation, snow, and ground freezing affect the availability of sand for transport by wind. Study results suggest that event-scale research is needed for understanding interactions between variables and the foredune, but mesoscale studies such as this one are crucial for identifying cumulative patterns of dune change and the role that events play in the larger scale patterns of dune evolution.

Remote sensing and geospatial analysis techniques allow for better understanding of dynamic landforms such as sand dunes. Our study investigated to what extent geospatial analysis of historic aerial photographs could be used to detect changes in dune activity over time at three Lake Michigan parabolic dunes in western Michigan, USA. We georeferenced historic aerial photographs, dating from 1938 to 2008, and then used edge-detection in remote sensing software ERDAS Imagine to distinguish bare sand from vegetated areas. The photos were then imported into the geographic information system ArcGIS, where they were reclassified and vectorized to create bare-sand outlines. Further analysis in ArcGIS allowed us to determine the changes over time to the bare-sand areas and the movement of the edges between bare sand and vegetation along the central axis of the dunes. Results show significant variability in each dune's bare-sand area during the study period, although only small increases in bare-sand area were recorded from the beginning to the end of the study. An indicator of continuing dune activity is the eastward advance of the inland edge of each bare-sand area from 1938 to 2008. Understanding changes in dune activity, especially long-term variation, through utilizing these geospatial technologies offers new insights and opportunities for research in the ongoing study and management of west Michigan dunes.

Ground penetrating radar (GPR) records of groundwater surface (GWS) reflections have been analyzed from 40 across-barrier profiles, totaling 50 km in combined length, taken from barrier spits and beach plains of the Columbia River littoral system. The barriers and beach plains host shallow fresh-water aquifers in the prograded beach deposits and abandoned foredune ridges, totaling 10–30 m in thickness. Study results demonstrate that GWS reflections could be traced continuously at subsurface depths of 1–15 m with the GPR 100 MHz and 50 MHz antennae using 400 V and 1000 V transmitters. Boreholes (62 in number) and lake water levels (24 in number) provide ground-truthing of the across-barrier GWS trends interpreted from the GPR profiles. The GWS rises in elevation (4–8 m above base level) under high, broad foredune-ridges and drops under interdune ridge valleys (1–3 m above base level). Continuous profiles of GWS demonstrate that lakes, ponds, and bogs of the barriers and beach plains are “windows” into the shallow coastal aquifer. The GPR records demonstrate that the GWS slopes either to seaward (0.003–0.04 gradient) or to landward (0.001–0.05 gradient) from divides under the largest, shore-parallel dune ridges in the barriers. The GWS gradients indicate that subsurface contaminant transport from the developed dune ridges will be intercepted by intervening lakes and ponds in the interdune-ridge valleys. The GPR records also establish the effect of drainage ditches in lowering GWS elevations (1–2 m) in sensitive wetlands located 100s of meters in distance from the constructed ditches.