Despite increased Atlantic hurricane risk, projected trends in hurricane frequency in the warming climate are still highly uncertain, mainly due to short instrumental record that limits our understanding of hurricane activity and its relationship to climate. Here we extend the record to the last millennium using two independent estimates: a reconstruction from sedimentary paleohurricane records and a statistical model of hurricane activity using sea surface temperatures (SSTs). We find statistically significant agreement between the two estimates and the late 20th century hurricane frequency is within the range seen over the past millennium. Numerical simulations using a hurricane-permitting climate model suggest that hurricane activity was likely driven by endogenous climate variability and linked to anomalous SSTs of warm Atlantic and cold Pacific. Volcanic eruptions can induce peaks in hurricane activity, but such peaks would likely be too weak to be detected in the proxy record due to large endogenous variability.

Sinkholes develop on carbonate landscapes when caves collapse and can subsequently become lake-like environments if they are flooded by local groundwater. Sediment cores retrieved from sinkholes have yielded high-resolution reconstructions of past environmental change, hydroclimate, and hurricane activity. However, our understanding of the internal sedimentary processes of these systems remains incomplete. Here, we use a multiproxy approach including sedimentology (stratigraphy, coarse-grained particle density, bulk organic matter content), micropaleontology (ostracods), and geochemistry (δ13C and δ2H on n-alkanoic acids) to reconstruct evidence for paleolimnology and regional hydroclimate from a continuous stratigraphic record (Emerald Pond sinkhole) in the northern Bahamas that spans the middle to late Holocene. Basal peat at 8.9 m below modern sea level documents the maximum sea-level position at 8200 cal. yr BP. Subsequent upward vertical migration of the local aquifer caused by regional sea-level rise promoted carbonate-marl deposition from 8300 to 1700 cal. yr BP. A shift in coarse particle deposition and ostracods at 5500 cal. yr BP suggests some environmental change, which may be related to one or multiple internal or external drivers. Sapropel deposition from 1700 to 1300 cal. yr BP indicates a fundamental change in limnology to promote increased organic matter preservation, perhaps related to the regional cooling during the Dark Ages Cold Period. We find δ2H28 values are largely invariant from 7700 to 6150 cal. yr BP suggesting a generally stable hydroclimate (mean − 133‰, 1σ = 5‰). The shift to more depleted values (− 156‰, 1σ = 19‰) at 6000–4800 cal. yr BP may be linked to a weakened (eastern displaced) North Atlantic Subtropical High. Nevertheless, additional local hydroclimate records are needed to better disentangle uncertainties from either internal or external influences on the resultant measurements.

Abandoned river channels on alluvial floodplains represent areas where sediments, organic matter, and pollutants preferentially accumulate during overbank flooding. Theoretical models describing sedimentation in floodplain lakes recognize the different stages in their evolution, where the threshold for hydrological connectivity increases in older lakes as a plug-bar develops. Sedimentary archives collected from floodplain lakes are widely used to reconstruct ecological and hydrological dynamics in riverine settings, but how floodplain lake evolution influences flow velocities and sedimentation patterns on an event scale remains poorly understood. Here we combine sediment samples collected in and around a floodplain lake with hydraulic modelling simulations to examine inundation, flow velocity, and sedimentation patterns in a floodplain lake along the Trinity River at Liberty, Texas. We focus our analyses on an extreme flood event associated with the landfall of Hurricane Harvey in August 2017 and develop a series of alternative lake bathymetries to examine the influence of floodplain lake evolution on flow velocity patterns during the flood. We find that sediments deposited in the lake after the Hurricane Harvey flood become thinner and finer with distance from the tie-channel in accordance with simulated flow velocities that drop with distance from the tie-channel. Flow velocity simulations from model runs with alternative plug-bar geometries and lake depths imply that sedimentation patterns will shift as the lake evolves and infills. The integration of sediment sampling and hydraulic model simulations provides a method to understand the processes that govern sedimentation in floodplain lakes during flood events that will improve interpretations of individual events in sedimentary archives from these contexts.

The collapse of the Maya civilization in the late 1st/early 2nd millennium CE has been attributed to multiple internal and external causes including overpopulation, increased warfare, and environmental deterioration. Yet the role hurricanes may have played in the fracturing of Maya socio-political networks, site abandonment, and cultural reconfiguration remains unexplored. Here we present a 2200 yearlong hurricane record developed from sediment recovered from a flooded cenote on the northeastern Yucatan peninsula. The sediment archive contains fine grain autogenic carbonate interspersed with anomalous deposits of coarse carbonate material that we interpret as evidence of local hurricane activity. This interpretation is supported by the correlation between the multi-decadal distribution of recent coarse beds and the temporal distribution of modern regional landfalling storms. In total, this record allows us to reconstruct the variable hurricane conditions impacting the northern lowland Maya during the Late Preclassic, Classic, and Postclassic Periods. Strikingly, persistent above-average hurricane frequency between ~ 700 and 1450 CE encompasses the Maya Terminal Classic Phase, the declines of Chichén Itza, Cobá, and subsequent rise and fall of the Mayapán Confederacy. This suggests that hurricanes may have posed an additional environmental stressor necessary of consideration when examining the Postclassic transformation of northern Maya polities.

Islands across the Bahamian Archipelago have been devastated by five major hurricanes from 2010 to 2020 CE, including Category 5 Hurricane Dorian in 2019 that inundated parts of Abaco and Grand Bahama with up to 4 m of surge, killing 84 people and leaving >245 others missing. Up to 1 m relative sea-level rise is estimated for The Bahamas by 2100 CE, which could enhance flooding from weaker storms (= Category 1 hurricanes passing within 115 km during the 170-year instrumental record (1850 CE-present) and may also document intense tropical or winter storms. Hine's Hole archives similar to 16 intense storms per century from 1850 to 2016 CE, but documents three periods from 1505 to 1530 CE, 1570 to 1620 CE, and similar to 1710 to 1875 CE with over twice as many intense storms per century. These active periods correspond to other high-resolution reconstructions from the Bahamian Archipelago and Florida Keys, but the magnitude of the increase is much higher given that Hine's Hole archives evidence of weaker and more distal storms. As such, this reconstruction provides unprecedented insight into changes in hurricane activity within the pre-industrial climate system and demonstrates that recurrence intervals based on the 170-year instrumental record can severely underestimate the threat hurricanes pose certain localities.

The impact of global environmental change on coral reef islands is uncertain, with few studies having resolved the critical controls on island formation and change. Based on detailed, topographic surveys, sediment analysis and radiometric dating, we present a multi-phase model of the formation of two reef islands in Jaluit atoll, Republic of the Marshall Islands. The initial phase of island building occurred 1300 years ago, later than elsewhere in the Marshall Islands and during a period of relative sea level fall from the mid-Holocene sea level highstand. Initial accumulation occurred as a consequence of relative emergence of the reef flat that forced a transition in reef flat ecology and dominant foraminifera sediment producers that contributed to island building. Distinctive sets of progradational ridges and their coarse sediment character provide evidence for the importance of extreme wave events in island expansion from an initial core. Expansion occurred in two principle phases, 650-350 years ago and 200 years ago to the present, each coincident with known phases of increased storminess in the central Pacific. Results highlight the complexity of island formation and show that future change will depend not only on sea level but storm processes that have been a major influence on island development over the past 650 years. Anticipated reduction in cyclogenesis in the southern Marshall Islands region suggests a near-future period of geomorphic stasis of the islands of Jaluit. An increase in cyclogenesis in the central Pacific and higher latitudes may enhance opportunities for storm-driven island accumulation events over the next century where coral growth is able to be maintained.

Meridional shifts of the North Atlantic Subtropical High (NASH) western edge create a dipole that drives hydroclimate variability in the southeastern United States and Caribbean region. Southwest displacements suppress rainfall in the southern Caribbean. Northwest displacements drive southeast United States and northern Caribbean drying. Projections for the 21st century suggest a more meridionally displaced NASH, which jeopardizes Caribbean island communities dependent on rain‐fed aquifers. While recent work indicates that Atlantic and Pacific Ocean‐atmosphere variability influenced the NASH during the instrumental period, little is known about NASH behavior and subsequent hydroclimate responses over longer timescales. To address this limitation, we developed a ∼6000‐years long rainfall record through the analysis of calcite raft deposits archived within sediments from a coastal sinkhole in the northeast Bahamas (Abaco Island). Increased (decreased) calcite raft deposition provides evidence for increased (decreased) rainfall driven by NASH variability. We use simulations from the Community Earth System Model to support this interpretation. These simulations improve our understanding of NASH behavior on timescales congruous with the reconstruction and suggest an important role for the state of the Pacific Ocean. Furthermore, model simulations and a compilation of regional hydroclimate reconstructions reveal that the NASH‐driven dipole dominates northern and southern Caribbean rainfall on centennial timescales. These results bring Holocene Caribbean hydroclimate variability into sharper focus while providing important context for present and future changes to regional climate. Additionally, this study highlights the need for improved future predictions of the state of the Pacific Ocean to best inform water scarcity mitigation strategies for at‐risk Caribbean communities.

Coastal communities are vulnerable to sea-level rise and hurricane-induced flooding. Our ability to assess flooding risk at coastal locations is restricted by the short observational record and limited knowledge on storm surge generation during hurricanes of different strength, size and orientation. Here, we present a transect of sediment cores collected from a blue hole near Middle Caicos in the Turks & Caicos Islands. Storm deposits found across cores in the transect record the passage of hurricanes passing to the south of Middle Caicos over the past 1500 years including Hurricane Irma in 2017. The record indicates historically unprecedented multi-decadal periods of elevated storm strikes on the island. We add this new reconstruction to a compilation of near-annually resolved paleohurricane records of the past millennium in The Bahamas. This compilation indicates increased storm activity in The Bahamas from 650 to 800 CE, 930 to 1040 CE, and 1400 to 1800 CE. Taken together with compilations of published paleohurricane records from New England and the Gulf Coast of Florida, we observe periods of elevated hurricane activity in all three spatially disparate regions over the past millennium and periods when New England and the Bahama Archipelago are active while the Gulf Coast of Florida is not. We argue that both regional-scale changes in vertical wind shear patterns and shifting storm tracks may explain the discrepancies we observe between different regions of the North Atlantic. This research informs how hurricane frequency has changed over the past 1500 years specifically in the Turks & Caicos Islands and regionally along the Bahama Archipelago.

The instrumental record reveals that tropical cyclone activity is sensitive to oceanic and atmospheric variability on inter-annual and decadal scales. However, our understanding of the influence of climate on tropical cyclone behaviour is restricted by the short historical record and the sparseness of prehistorical reconstructions, particularly in the western North Pacific, where coastal communities suffer loss of life and livelihood from typhoons annually. Here, to explore past regional typhoon dynamics, we reconstruct three millennia of deep tropical North Pacific cyclogenesis. Combined with existing records, our reconstruction demonstrates that low-baseline typhoon activity prior to 1350 ce was followed by an interval of frequent storms during the Little Ice Age. This pattern, concurrent with hydroclimate proxy variability, suggests a centennial-scale link between Pacific hydroclimate and tropical cyclone climatology. An ensemble of global climate models demonstrates a migration of the Pacific Walker circulation and variability in two Pacific climate modes during the Little Ice Age, which probably contributed to enhanced tropical cyclone activity in the tropical western North Pacific. In the next century, projected changes to the Pacific Walker circulation and expansion of the tropics will invert these Little Ice Age hydroclimate trends, potentially reducing typhoon activity in the deep tropical Pacific. Atmospheric circulation shifts during the Little Ice Age led to greater typhoon generation in the tropical North Pacific according to a comparison of sediment proxy records of past storm activity and outputs of general circulation models.

Hurricane Michael (2018) was the first Category 5 storm on record to make landfall on the Florida panhandle since at least 1851 CE (Common Era), and it resulted in the loss of 59 lives and $25 billion in damages across the southeastern U.S. This event placed a spotlight on recent intense (exceeding Category 4 or 5 on the Saffir-Simpson Hurricane Wind Scale) hurricane landfalls, prompting questions about the natural range in variability of hurricane activity that the instrumental record is too short to address. Of particular interest is determining whether the frequency of recent intense hurricane landfalls in the northern Gulf of Mexico (GOM) is within or outside the natural range of intense hurricane activity prior to 1851 CE. In this study, we identify intense hurricane landfalls in northwest Florida during the past 2000 years based on coarse anomaly event detection from two coastal lacustrine sediment archives. We identified a historically unprecedented period of heightened storm activity common to four Florida panhandle localities from 650 to 1250 CE and a shift to a relatively quiescent storm climate in the GOM spanning the past six centuries. Our study provides long-term context for events like Hurricane Michael and suggests that the observational period 1851 CE to present may underrepresent the natural range in landfalling hurricane activity.

The northern Bahamas have experienced more frequent intense-hurricane impacts than almost anywhere else in the Atlantic since 1850 CE. In 2019, category 5 (Saffir-Simpson scale) Hurricane Dorian demonstrated the destructive potential of these natural hazards. Problematically, determining whether high hurricane activity levels remained constant through time is difficult given the short observational record (< 170 years). We present a 700-year long, near-annually resolved stratigraphic record of hurricane passage near Thatchpoint Blue Hole (TPBH) on Abaco Island, The Bahamas. Using longer sediment cores (888 cm) and more reliable age-control, this study revises and temporally expands a previous study from TPBH that underestimated the sedimentation rate. TPBH records at least 13 ≥ category 2 hurricanes per century between 1500 to 1670 CE, which exceeds the 9 ≥ category 2 hurricanes per century within 50 km of TPBH since 1850 CE. The eastern United States also experienced frequent hurricanes from 1500 to 1670 CE, but frequency was depressed elsewhere in the Atlantic Ocean. This suggests that spatial heterogeneity in Atlantic hurricane activity since 1850 CE could have persisted throughout the last millennium. This heterogeneity is impacted by climatic and stochastic forcing, but additional high-resolution paleo-hurricane reconstructions are required to assess the mechanisms that impact regional variability.

The sediment in North Atlantic blue holes preserves paleoclimate records. However, accurate paleoclimate reconstructions require an improved understanding of allogenic versus autogenic processes controlling blue hole sedimentation. Here we provide a detailed case study of the Holocene stratigraphy within Freshwater River Blue Hole, which is currently surrounded by carbonate tidal flats in the northern Bahamas (Abaco Island). During the Holocene, concomitant coastal aquifer elevation and relative sea-level rise controlled internal blue hole depositional environments. The general Holocene facies succession observed is: (i) basal detrital and freshwater peat, (ii) palustrine to lacustrine marl, (iii) algal sapropel, and finally (iv) bedded carbonate mud. During the middle Holocene when groundwater levels were lower, small changes in accommodation space that were inherited from the bedrock surface below (< 1 m) were able to promote significant lateral facies changes. Multiple cores are needed to characterize these lateral facies changes. Hydrographic characteristics of the coastal aquifer (e.g., vertical position, stratification, salinity) relative to the blue hole benthos exert a fundamental control on (a) benthic flora and meiofauna (e.g., charophytes, ostracodes, foraminifera, gastropods) and (b) organic matter production and preservation from pelagic productivity. Over the last 5000 years, water column stratification in Freshwater River Blue Hole was interrupted on millennial to sub-decadal timescales, which are potentially linked to changing aquifer recharge and rainfall. Lastly, historical intense hurricanes passing closely to the west of the site may have promoted deposition of coarse beds at the site. However, the lack of carbonate tidal flat microfaunal remains (foraminifera: Peneroplis) within these coarse intervals indicates that Freshwater River Blue Hole does not preserve a reliable record of hurricane-induced overwash deposition from the carbonate tidal flats during the last 2300 years.

The Little Bahama Bank was likely the last island group colonized by the Lucayan natives in the tropical North Atlantic, but preserved Lucayan remains are rare from this region. Furthermore, the Lucayan diet included both marine and terrestrial contributions, which must be considered when calibrating conventional radiocarbon results from human remains into Common Era (CE) calendar years. Here we present a new discovery of Lucayan remains (proximal epiphysis of a right tibia) identified within a sinkhole on Great Abaco Island in the northern Bahamas, which was preserved in the extremely well-dated sedimentary infill (dated with 22 independent radiocarbon ages). The age of the human tibia was estimated through both the associated stratigraphy (relative age), and direct radiocarbon dating of the bone (absolute age). The direct age of the bone was calibrated by using a two-endmember mixing model to estimate the average proportion of marine versus terrestrial contributions to this individuals' diet using the delta C-13 value of the bone collagen and applying a local Delta R value for regional aquatic settings. Absolute dating places the age of the remains from Great Cistern between 1255 and 1340 CE (2 sigma, probability: 0.89). Applying the same mixing model to the previously discovered remains from Sawmill Sink on Great Abaco Island indicates those remains are in fact 100 to 200 years younger than the previous estimate with internment likely occurring between 1110 and 1290 CE (2 sigma, probability: 0.95).

This study contributes baseline information regarding the framework geology, drivers of coastal change, and archaeological record along the fjord-indented coastlines of southcentral Alaska. Field data were collected in July 2015 from James Lagoon, a 30-m-deep drowned cirque valley adjacent to McCarty Fjord in the Nuka Bay region of Kenai Fjords National Park. A 1790 CE terminal moraine deposited by McCarty Glacier extends across the cirque opening and delimits the lagoon. Acoustic surveys of the lagoon reveal bedrock overlain by deltaic, lacustrine, and marine facies containing beds that indicate past submarine landslides. Lagoon and marsh sediment cores contain coarse sand horizons interbedded with silt and peat, evidence of repeated low-frequency, high-intensity events. The largest of the event beds in the marine cores occurs near the surface and is likely associated with the 1964 Great Alaska Earthquake (moment magnitude 9.2). Trees killed during the 1964 earthquake fringe the coastline and indicate similar to 2m of coseismic subsidence. Radiocarbon ages of five exposed subfossil stumps indicate two pre-1964 subsidence events occurring between 1710 and 1789 and 1078 and 1125 median probability calendar year CE (cal CE). A Sugpiaq culture archaeological site dated to 1565 cal CE existed on the western shore of James Lagoon in the interval between these two events, possibly for proximity to an ice floe harbor seal rookery at McCarty Glacier. Archaeological site elevation above mean high water at James Lagoon and around Nuka Bay is inversely related to the extent of cumulative site erosion caused by coastal submergence during the last two great earthquakes. These combined findings lay the groundwork for future research and provide context to ongoing coastal hazards and their effects on cultural resources.