Brendan Reilly

Lamont-Doherty Earth Observatory

Over the last decade, two major calving events of the Petermann Ice Tongue in Northwest Greenland have led to speculation on its future stability and contribution to further Greenland Ice Sheet mass loss. However, it has been unclear if these events are anomalous or typical within the context of limited historical observations. We extend the histor...

International Ocean Discovery Program (IODP) Expedition 382 in the Scotia Sea’s Iceberg Alley recovered among the most continuous and highest resolution stratigraphic records in the Southern Ocean near Antarctica spanning the last 3.3 Myr. Sites drilled in Dove Basin (U1536/U1537) have well‐resolved magnetostratigraphy and a strong imprint of orbit...

We document magnetic mineral diagenesis with high resolution magnetic susceptibility, hysteresis, isothermal remanent magnetization, and other rock magnetic measurements through a shallow sulfate‐methane transition (SMT) at Perseverance Drift—a high‐accumulation rate Holocene biosiliceous Antarctic marine sediment deposit. The structure of the SMT...

We investigate chronology and age uncertainty for the middle to upper Pleistocene lower Bengal Fan using a novel age‐depth modeling approach that factors lithostratigraphic, magnetostratigraphic, biostratigraphic, cyclostratigraphic, and seismic stratigraphic constraints, based on results from the International Ocean Discovery Program Expedition 35...

We investigate full vector paleomagnetic changes recorded in high‐resolution sediments of Petermann Fjord, North Greenland, deposited over the last 6 kyr, in the context of the recent rapid changes in the geomagnetic field. A Paleomagnetic Secular Variation (PSV) stack (inclination, declination, and relative paleointensity) was reconstructed using...

Marine fallout ash beds can provide continuous, time‐precise records of highly explosive arc volcanism that can be linked with the climate record. An evaluation of revised Plio‐Pleistocene (0–4 Myr) tephrostratigraphies from Ocean Drilling Program Sites 881, 882, and 884 confirms cyclicity of the Kamchatka‐Kurile arc volcanism and a marked increase...

Over the last 3.3 million years, the Antarctic Ice Sheet (AIS) has undergone phases of ice sheet growth and decay, impacting sea level and climate globally. Presently, the largely marine‐terminating AIS loses mass primarily by iceberg calving and basal melt of ice shelves. Quantifying past rates and timing of AIS melt is vital to understanding futu...

We document an apparent downward displacement of the Matuyama‐Brunhes magnetic reversal by ∼20 m at Scotia Sea International Ocean Discovery Program Site U1538 (Pirie Basin) by comparison with the well‐defined paleomagnetic record at nearby Site U1537 (Dove Basin). Detailed stratigraphic correlation between the two sites is possible due to similar...

We investigate the amplitude and frequency of directional geomagnetic change since 15 ka in the Northern North Atlantic (∼67°N) using five “ultra‐high” resolution continental shelf sediment cores deposited at rates greater than 1 m/kyr. The ages of these cores are constrained by 103 radiocarbon dates with reservoir ages assessed through tephra corr...

Antarctica is one of the most vulnerable regions to climate change on Earth and studying the past and present responses of this polar marine ecosystem to environmental change is a matter of urgency. Sedimentary ancient DNA (sedaDNA) analysis can provide such insights into past ecosystem-wide changes. Here we present authenticated (through extensive...

Relative Sea Levels (RSLs) derived primarily from marine bivalves near Petermann Glacier, NW Greenland, constrain past regional ice-mass changes through glacial isostatic adjustment (GIA) modeling. Oxygen isotopes measured on bivalves corrected for shell-depth habitat and document changing meltwater input. Rapid RSL fall of up to 62 m/kyr indicates...

Early Pleistocene Marine Isotope Stage (MIS)‐31 (1.081–1.062 Ma) is a unique interval of extreme global warming, including evidence of a West Antarctic Ice Sheet (WAIS) collapse. Here we present a new 1,000‐year resolution, spanning 1.110–1.030 Ma, diatom‐based reconstruction of primary productivity, relative sea surface temperature changes, sea‐ic...

Ice loss in the Southern Hemisphere has been greatest over the past 30 years in West Antarctica. The high sensitivity of this region to climate change has motivated geologists to examine marine sedimentary records for evidence of past episodes of West Antarctic Ice Sheet (WAIS) instability. Sediments accumulating in the Scotia Sea are useful to exa...

The Southern Ocean paleoceanography provides key insights into how iron fertilization and oceanic productivity developed through Pleistocene ice-ages and their role in inbuencing the carbon cycle. We report the crst high-resolution record of dust deposition and ocean productivity for the Antarctic Zone, close to the main dust source, Patagonia (Fig...

Based on sediment cores and geophysical data collected from Petermann Fjord and northern Nares Strait, NW Greenland, an Arctic ice shelf sediment facies is presented that distinguishes sub and pro ice shelf environments. Sediment cores were collected from sites beneath the present day Petermann Ice Tongue (PIT) and in deglacial sediments of norther...

During the last deglaciation substantial volumes of meltwater from the decaying Laurentide Ice Sheet were supplied to the Arctic, Gulf of Mexico and North Atlantic along different drainage routes, sometimes as catastrophic flood events. These events are suggested to have impacted global climate, for example initiating the Younger Dryas cold period....

The Southern Ocean paleoceanography provides key insights into how iron fertilization and oceanic productivity developed through Pleistocene ice-ages and their role in influencing the carbon cycle. We report a high-resolution record of dust deposition and ocean productivity for the Antarctic Zone, close to the main dust source, Patagonia. Our deep-...

Recent advancements in marine sedimentary ancient DNA (sedaDNA) techniques now enable detection of rare eukaryote taxa in deep ocean sediments. To be determined, however, is how far back in time these taxa can be detected. Here, we present the first authenticated (through sedaDNA damage analysis) metagenomic marine eukaryote sedaDNA from the Scotia...

The Southern Ocean paleoceanography provides key insights into how iron fertilization and oceanic productivity developed through Pleistocene ice-ages and their role in influencing the carbon cycle. We report the first high-resolution record of dust deposition and ocean productivity for the Antarctic Zone, close to the main dust source, Patagonia. O...

The eastern Scotia Sea is known as Iceberg Alley, where large numbers of icebergs are brought to the Antarctic Circumpolar Current via the Weddell Sea Gyre. Icebergs transported through Iceberg Alley today can have traveled in the coastal current from anywhere around the Antarctica margin, but are sourced mostly from the Weddell Sea sector. The Wed...

The Southern Ocean paleoceanography provides key insights into how iron fertilization and oceanic productivity developed through Pleistocene ice-ages and their role in influencing the carbon cycle. We report the first high-resolution record of dust deposition and ocean productivity for the Antarctic Zone, close to the main dust source, Patagonia. O...

IODP Exp. 382 in the Scotia Sea’s Iceberg Alley recovered among the most continuous and highest resolution stratigraphic records in the Southern Ocean near Antarctica from 3.3 Ma to present. These deep sea contourite deposits have lithologic alternations between terrigenous and diatomaceous facies which reflect Antarctic Ice Sheet and Southern Ocea...

International Ocean Drilling Program (IODP) Expedition 341 recovered sediments from the south Alaska continental slope that preserves a well resolved and dated inclination record over most of the past ∼43,000 years. The Site U1419 chronology (Walczak et al., 2020) is among the highest resolution in the world, constrained by 173 radiocarbon dates, p...

The Antarctic Circumpolar Current (ACC) acts as a critical component to regulate the global thermohaline circulation and climate. However, active debate remains about the relative strength of ACC during current/past warm periods and underlying driving mechanisms. Here, we present sortable silt mean grain size records from the Scotia Sea to infer th...

The Petermann 2015 expedition to Petermann Fjord and adjacent Hall Basin recovered a transect of cores, extending from Nares Strait to underneath the 48 km long ice tongue of Petermann glacier, offering a unique opportunity to study ice–ocean–sea ice interactions at the interface of these realms. First results suggest that no ice tongue existed in...

Southern Ocean paleoceanography provides key insights into how iron fertilization and oceanic productivity developed through Pleistocene ice-ages and their role in influencing the carbon cycle. We report the first high-resolution record of dust deposition and ocean productivity for the Antarctic Zone, close to the main dust source, Patagonia. Our d...

The northern sector of the Greenland Ice Sheet is considered to be particularly susceptible to ice mass loss arising from increased glacier discharge in the coming decades. However, the past extent and dynamics of outlet glaciers in this region, and hence their vulnerability to climate change, are poorly documented. In the summer of 2019, the Swedi...

International Ocean Discovery Program (IODP) Site U1536 (proposed Site SCO-13) is located 235 km northwest of the South Orkney Islands at 59°26.46′S, 41°3.66′W in 3220 m of water. Site U1536 is the first of two sites drilled in Dove Basin, which is located in the southern Scotia Sea. This site was targeted to recover a com- plete Neogene record of...

International Ocean Discovery Program (IODP) Site U1535 (proposed Site SFSD-02A) is located on the northern flank of a large trough ~668 km east of the Strait of Magellan at 53°11.49′S, 58°38.60′W in 647 m of water. The site is situated at Common Depth Point 9220 on Seismic Reflection Profile SGFI93-107. Site U1535 is the second of a pair of sites....

This section provides an overview of operations, depth conven- tions, core handling, curatorial procedures, and analyses performed on the R/V JOIDES Resolution during International Ocean Discov- ery Program (IODP) Expedition 382. This information applies only to shipboard work described in the Expedition reports section of the Expedition 382 Procee...

International Ocean Discovery Program Expedition 382, Iceberg Alley and Subantarctic Ice and Ocean Dynamics, investigated the long-term climate history of Antarctica, seeking to understand how polar ice sheets responded to changes in insolation and atmospheric CO2 in the past and how ice sheet evolution influenced global sea level and vice versa. F...

International Ocean Drilling Program (IODP) Site U1538 (pro- posed Site SCO-11) is located 365 km north-northeast of the South Orkney Islands at 57°26.52′S, 43°21.47′W in 3131 m of water. The site lies in Pirie Basin and is situated at Shotpoint 4900 on Seismic Reflection Profile SCAN2013-13, 9 km east of Crossing Line SCAN2013-11. Site U1538 is lo...

International Ocean Discovery Program (IODP) Site U1534 (proposed Site SFSD-03A) is located at 53°11.38′S, 58°45.65′W in 605 m of water. The site is situated on the northern flank of an east– west trending trough on the continental shelf ~660 km east of the Strait of Magellan at Common Depth Point 10005 on Seismic Re- flection Profile SGFI93. Site...

International Ocean Discovery Program Expedition 382, Ice- berg Alley and Subantarctic Ice and Ocean Dynamics, investigated the long-term climate history of Antarctica, seeking to understand how polar ice sheets responded to changes in insolation and atmo- spheric CO2 in the past and how ice sheet evolution influenced global sea level and vice vers...

International Ocean Drilling Program (IODP) Site U1537 (pro- posed Site SCO-18) is located 265 km northwest of the South Or- kney Islands at 59°6.65′S, 40°54.37′W in 3713 m of water. The site lies in the northeast part of Dove Basin in a ~1 km thick contourite drift and is situated at Shotpoint 4900 on Multichannel Seismic (MCS) Reflection Profile...

The northern sector of the Greenland ice sheet is considered to be particularly susceptible to ice mass loss arising from increased glacier discharge in the coming decades. However, the past extent and dynamics of outlet glaciers in this region, and hence their vulnerability to climate change, are poorly documented. In the summer of 2019, the Swedi...

The Petermann 2015 Expedition to Petermann Fjord and adjacent Hall Basin recovered a transect of cores from Nares Strait to under the 48 km long ice tongue of Petermann glacier, offering a unique opportunity to study ice-ocean-sea ice interactions at the interface of these realms. First results suggest that no ice tongue existed in Petermann Fjord...

Scotia Sea and the Drake Passage is key towards understanding the development of modern oceanic circulation patterns and their implications for ice sheet growth and decay. The sedimentary record of the southern Scotia Sea basins documents the regional tectonic, oceanographic and climatic evolution since the Eocene. However, a lack of accurate age e...

Location, Location, Location: Turbidite stratigraphy at the interface between paleoseismic and paleoclimate records C. Goldfinger. M. Walczak, V. Sahakian, Brendan Reilly, Saray Valdez Hernandez Paleoseismic turbidites along the Cascadia margin are spatially restricted, more so than one might expect. Excellent high-resolution records are found in...

Magnetic susceptibility (k) records from Scotia Sea deep water contourites are remarkably similar to atmospheric dust flux records in East Antarctic ice cores, suggesting Scotia Sea contourite evolution and atmospheric dust transport are responding to common forcing mechanisms. Glacial-marine k records reflect the interplay of lithogenic sediment p...

The processes controlling advance and retreat of outlet glaciers in fjords draining the Greenland Ice Sheet remain poorly known, undermining assessments of their dynamics and associated sea-level rise in a warming climate. Mass loss of the Greenland Ice Sheet has increased six-fold over the last four decades, with discharge and melt from outlet gla...

We document magnetic mineral diagenesis with high‐resolution magnetic susceptibility, hysteresis, isothermal remanent magnetization, and other rock magnetic measurements through a shallow sulfate‐methane transition (SMT) at Perseverance Drift—a high‐accumulation rate Holocene biosiliceous Antarctic marine sediment deposit. The structure of the SMT...

Calving events of Petermann Glacier, northwest Greenland, in 2010 and 2012 reduced the length of its ice tongue by c. 25 km, allowing exploration of newly uncovered seafloor during the Petermann 2015 Expedition. This article presents the results of foraminiferal analysis and environmental data from thirteen surface sediment samples in northern Nare...

Approximately 74 ka, Toba caldera in Sumatra, Indonesia, erupted in one of the most catastrophic supereruptions in Earth's history. Resurgent uplift of the caldera floor raised Samosir Island 700 m above Lake Toba, exposing valuable lake sediments. To constrain sediment chronology, we collected 173 discrete paleomagnetic 8 cm 3 cubes and 15 radioca...

International Ocean Discovery Program (IODP) Expedition 354 Site U1450 was drilled at the center of a transect of 7 sites across the Bengal Fan at 8°N where long-term accumulation rates are highest. Site U1450 primarily consists of sandy and silty-sandy turbidites deposited at a rate higher than 20 cm/ky. During periods when the depocenter shifted...

Patterns of variability in Pleistocene magnetic susceptibility (k) from deep-sea sediment cores from the Scotia Sea show a striking similarity to patterns of dust flux recorded in the EPICA Dronning Maud Land (EDML) ice core. Antarctic marine k records broadly reflect the interplay of lithogenic sediment provenance, biological productivity, sedimen...

This study reports the presence of Australasian microtektites in a deep-sea core (U1452) retrieved during the International Ocean Discovery Program (IODP) Expedition 354: Bengal Fan. These microtektites are found within a foraminifer-rich calcareous clay layer beneath the Matuyama-Brunhes (M–B) magnetostratigraphic boundary. The majorities are sphe...

We present and make publicly available a dynamic programming algorithm to simultaneously align the inclination and declination vector directions of sedimentary palaeomagnetic secular variation data. This algorithm generates a library of possible alignments through the systematic variation of assumptions about the relative accumulation rate and shar...

Recent International Ocean Discovery Program (IODP) drilling in the Scotia Sea’s “Iceberg Alley” at Sites U1536 and U1537 recovered stratigraphic records from the late Pliocene to the Holocene and represent some of the most continuous and highest resolution records ever recovered near Antarctica. These records have excellent magnetostratigraphy and...

Petermann Fjord is a deep (>1000 m) fjord that incises the coastline of north-west Greenland and was carved by an expanded Petermann Glacier, one of the six largest outlet glaciers draining the modern Greenland Ice Sheet (GrIS). Between 5 and 70 m of unconsolidated glacigenic material infills in the fjord and adjacent Nares Strait, deposited as the...