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Member Berry

Member Berry

Description
Member Berry is an Indica-dominant hybrid known for creating a long-lasting and floaty high. This strain is bred from a Skunkberry x Mandarin Sunset pairing and features beautifully dense green buds that are easy to work with.

Physical Effects
Euphoric, relaxing, appetite-stimulating.

Flavor
The flavor is tart and fruity, with a sweet citrus finish.

Member Berry is a hybrid of Skunk Berry and Mandarin Sunset. With sweet and tart citrus flavors, Member Berry has heavy, long-lasting hybrid effects.

Jonny Kingslake

Jonny Kingslake

Lamont-Doherty Earth Observatory

We are looking for a graduate student for a fall 2021 start

Henry Ice Rise, 2015

We are looking for a graduate student for a fall 2021 start

Biography

I grew up in Reading UK, 20 minutes by train from London. I went to Chiltern Edge Secondary School (11-16yrs) and Henley Sixth Form College (17-18yrs).

After two years of working and backpacking I went to The University of York, UK, and did a Physics BSc. My final year project was on the nucleation of freezing in supercooled water, supervised by Dr Richard Keesing. We scattered a laser through droplets of supercooled water to observed freezing as it was initiated by the application of an electric field.

Between 2009 and 2013 I did PhD in glaciology in the Department of Geography, Sheffield University, supervised by Dr Felix Ng. My thesis was entitled ‘Modeling ice-dammed lake drainage’ (pdf). I used mathematical models to study how water flows beneath glacier (see research section).

Between 2013 and 2016, was a Glacier Geophysicist at the British Antarctic Survey (BAS), Cambridge, UK. I was employed on a NERC-funded project led by Richard Hindmarsh. We used radar and mathematical models to study present-day and past ice flow in West Antarctica.

In March 2016 my wife and I moved from the UK and I started my current position as Assistant Professor in the Department of Earth and Environmental Sciences, Columbia University, and the Lamont-Doherty Earth Observatory.

My research is concerned with obtaining a better understanding of glacial processes to improve predictions of ice-sheet evolution.

I advise a group of students and post-docs using remote-sensing, mathematical modeling and fieldwork to better understand glacial processes.

People

Some details on the students and post-docs I help advise.

Elizabeth Case

Elizabeth started her PhD in 2017. She examines the deformation of ice through physical models and in-situ observations. Right now, she’s working on understanding how old snow (firn) turns into ice. She uses phase-sensitive radar measurements from around Antarctica to estimate how the ice stretches (deformation), and how quickly layers in the ice move down relative to each other (vertical strain rate). Disentangling this stretching signal from the vertical strain rate signal in the firn will help better constrain measurements of mass change. In her free time, she’s outside — climbing, hiking, or camping — or making digital art.

Julian Spergel

Graduate Research Assistant

Julian became interested in glaciology on a hot summer day in high school when his family’s air condition stopped working. What first was a means of escaping the heat became a livelong passion towards understanding the history of ice sheets and the mechanisms that control glacial stability. Julian received a BS in Geophysical Science from the University of Chicago in 2016 and subsequently began a PhD at Columbia University, advised by Jonathan Kingslake. His research interests include glacial hydrology, glacial history, and ice-climate interaction. Julian is currently a third-year graduate student and is researching the surface hydrology of the Amery Ice Shelf in East Antarctica.

Laura A. Stevens

Check out Laura’s websites here and here.

Laura’s research focuses on the physical processes driving ice-sheet flow, with a particular interest in the interactions between ice sheets, meltwater, and oceanic forcing. Laura’s main tools are in situ geodetic, atmospheric, and oceanographic observations paired with numerical models. She completed a PhD in Geophysics in the MIT/WHOI Joint Program with a thesis entitled “Influence of meltwater on Greenland Ice Sheet dynamics” in September 2017. For her thesis, she worked on string of problems including triggers for supraglacial lake drainage, decadal ice-sheet flow in response to melt, near-ice hydrography and observations of subglacial discharge in fjords, and numerical modeling of the subglacial drainage system. Since arriving at Lamont, she has focused on a couple of projects including diurnal fluctuations in flow of Helheim Glacier, East Greenland, and the dynamic response of ice shelves to sub-shelf channel incision.

Ching-Yao Lai

Yao studies hydrofractures in ice-shelves. Prior to joining Lamont she obtained her PhD degree in fluid mechanics from Princeton University in June 2018 with a thesis entitled “Fluid-Structure Interactions for Energy and the Environment.” She employed idealized mathematical models, laboratory experiments, and computational simulation to explore a range of problems involving the interplay between fluid flows, fractures, deformable elastic structures, and multiphase interfacial flows, with applications ranging from industry to climate. In 2018 she joined Lamont to apply her background in engineering and physics to study the processes responsible for collapsing ice shelves. She embraces new approaches to problems and particularly enjoys discoveries and surprises lying at the intersections of disciplines. She is now developing both physics-based and neural-network models to understand where ice fractures form and their interaction with surface meltwater.

Janette Levin

Janie is a junior studying Applied Math at Columbia University. She is working on a project modeling the evolution of surface topography around ice divides. Janie is interested in the intersection of remote-sensing and mathematical modeling, and is currently learning about both ends of the spectrum through analysis of topographical features that form on locations such as the Korff Ice Rise, West Antarctica.

Aleksandr (Sasha) Montelli

Sasha completed his PhD at the Scott Polar Research Institute at the University of Cambridge, with a thesis entitled “The Quaternary evolution of the mid-Norwegian continental margin.” During his graduate work, his research focused on geophysical and geological investigations of high-latitude continental margins to reconstruct former ice-sheet behaviour and understand long-term ice-ocean interactions in the Arctic and Antarctica. In 2019 he joined Lamont to pivot into the field of numerical ice-sheet modelling. Currently he is developing and analysing models of englacial thermal evolution of ice rises on the Antarctic Ice Sheet over the Holocene to better understand past ice-sheet evolution and to improve methods of ice-drilling site targeting.

Research Highlights

My research is focused on modelling and observing the flow of ice and water in ice sheets and glaciers.

Subglacial hydrology

During my PhD I studied the flow of water beneath glaciers and ice sheets through the development and analysis of mathematical models. I studied how ice-dammed lakes fill and drain beneath glaciers, showing how simple models can be used to predict approximately when lakes will drain, lakes can fill and drain chaotically and lakes affect the flow of glaciers through their impact on subglacial water pressures.

The Nye Attractor. This anaglyph, viewable with 3D glasses, shows the chaotic behavior of a model glacial lake. This is a section of an infinitely long curve called an attractor. It shows the evolution of a model glacial lake as it fills and drains, chaotically. The curve’s distance along the vertical black axis is the flow out of the lake, its distance from the axis is the lake’s depth and its rotation round the axis is time. It is named for the British glaciologist John Nye who devised the model in 1976. This anaglyph is designed to be viewed with 3D glasses. Kingslake, J. Chaotic dynamics of a glaciohydraulic model. J Glac. (61)227.

Glacier geophysics

My work at the British Antarctic Survey focused on using radar to constrain present and past ice flow in the Ronne Ice Shelf region of West Antarctica. We used a phase-sensitive radar system to measure an ice-dynamical phenomenon called the Raymond Effect.

We have used data from this radar to measure englacial ice flow and help to determine the history of ice flow in Antarctica.

Elizabeth Case is now using these data to measure the compaction of snow (and “firn”) into glacial ice.

Ice-sheet history

In 2018 I co-led a paper presenting evidence that the West Antarctic Ice Sheet was smaller than it is today during the Holocene, in both the Weddell Sea and Ross Sea sectors. This work was done as part of a team of 10 scientists from 5 institutions across 3 countries. We hypothesized that readvance was caused by the delayed response of the lithosphere to unloading following the Last Glacial Maximum. The evidence for this came from ice-penetrating radar and radiocarbon found in subglacial sediments, and we examined the implications of and controls on the readvance using a continent-wide ice-sheet model. The image below comes from the paper. It shows maximum and minimum grounding line positions predicted by the model.

In a paper from 2016, we used phase-sensitive radar and GPS to infer vertical and horizontal ice flow fields throughout the thickness of Korff Ice Rise, West Antarctica. We used these englacial flow fields with radar observations of internal layers within the ice rise to show that the flow of his part of the ice sheet underwent a reorganization around 2-3 kyr ago. Continued research into the history of the West Antarctic Ice Sheet is bringing together geophysical and sedimentological data with ice-sheet modelling, to understand large-scale change during the last few thousand years.

Supraglacial hydrology

Though my PhD work was focused on lakes that drain subglacially (beneath glaciers and ice sheets), I was also interested in surface melt ponds and how they drain supraglacially (across the surface of the ice). Both subglacial and supraglacial drainage can involve flow paths that grow due to frictional melting from the flowing water, so some aspects of these two types of drainage are similar. I modeled the physics of supraglacial drainage, finding that melt ponds can drain stably or unstably over the surface of the ice. Which style of drainage occurs depends on factors like the size and shape of ponds and the input to the lake from its catchment. This is potentially significant because these factors may vary systematically as the climate changes, and drainage style fundamentally impacts the amount of water that is drained towards the ocean. This work is published here.

At Lamont I have been able to revisit supraglacial hydrology. Throughout 2016 I, along with Lamont colleagues, explored the supraglacial hydrology (i.e. hydrology that goes on on the surface of ice) of Antarctica. This has been exciting because only a few previous studies have looked at water moving across the surface of Antarctica, but we concluded that surface water flow potentially has an important role to play in the future of the Antarctic Ice Sheet.

In two papers (here and here) recently published in Nature, and summarized in the same issue (here), we showed that water has been moving long distances onto and across many Antarctic Ice Shelves for many decades (possibly much longer).

Our research is now focused on understanding how these drainage systems operate and how they develop under changing environmental conditions. Julian Spergel, a PhD candidate in the Earth and Environmental Sciences department here at Columbia, is leading this work.

This animation shows a series of images taken by NASA’s LANDSAT7 satellite. Over a period of around 3 1/2 weeks this large pond on Amery Ice Shelf, East Antarctica, inundated an area of 55 square kilometers.

These observations of widespread supraglacial hydrology in Antarctica are interesting because as the continent warms, water could either move into areas where it can cause ice shelves to collapse, or it could evacuate water into the oceans as shown by one of our papers. The movie below, taken from a helicopter, shows a large water fall at the front of the Nansen Ice Shelf.

Publications

Peer-reviewed

Lai C.Y., J. Kingslake, M.G. Wearing, P-H. C. Chen, P. Gentine, H. Li, J. Spergel, M. van Wessem (2020) Vulnerability of Antarctica’s ice shelves to meltwater-driven fracture, Nature, 584(7822), 574–578. https://doi.org/10.1038/s41586-020-2627-8

Wearing, M.G., Kingslake, J. and Worster, M.G., Can unconfined ice shelves provide buttressing via hoop stresses? (2020) Journal of Glaciology, 1-13. https://doi.org/10.1017/jog.2019.101

Siegert, M.J., J. Kingslake, N. Ross, P.L. Whitehouse, J. Woodward, S.S. Jamieson, M.J. Bentley, K. Winter, M. Wearing, A.S. Hein, H. Jeofry (2019) Major ice sheet change in the Weddell Sea Sector of West Antarctica over the last 5,000 years. Reviews of Geophysics, 57, 1197– 1223. https://doi.org/10.1029/2019RG000651

Boghosian, A.L., M.J. Pratt, M.K. Becker, S.I. Cordero, T. Dhakal, J. Kingslake, C.D. Locke, K.J. Tinto, R.E. Bell (2019) Inside the ice shelf: using augmented reality to visualise 3D lidar and radar data of Antarctica. The Photogrammetric Record, 34(168), 346-364.(pdf)

Stubblefield, A.G., T. Creyts, J. Kingslake, M. Spiegelman (2019) Modeling oscillations in connected glacial lakes. Journal of Glaciology. 65(253), pp.745-758. https://doi.org/10.1017/jog.2019.46 (pdf)

Wearing, M.G. and J. Kingslake (2019) Holocene Formation of Henry Ice Rise, West Antarctica, Inferred from Ice‐Penetrating Radar. Journal of Geophysical Research: Earth Surface. 124, 8, 2224-2240, doi.org/10.1029/2018JF004988

Brisbourne, A.M., C. Martin, A.M. Smith, A.F. Baird, J.M. Kendall, J. Kingslake (2019) Constraining Recent Ice Flow History at Korff Ice Rise, West Antarctica, Using Radar and Seismic Measurements of Ice Fabric. Journal of Geophysical Research: Earth Surface, 124(1), 175-194 https://doi.org/10.1029/2018JF004776

Bell, R.E, A.F. Banwell, L.D. Trusel, J. Kingslake (2018) Antarctic surface hydrology and impacts on ice-sheet mass balance, Nature Climate Change, 8, 1044–1052 https://doi.org/10.1038/s41558-018-0326-3

Shackleton, C., H. Patton, A. Hubbard, M. Winsborrow, J. Kingslake, M. Esteves, K. Andreassen and S.L. Greenwood, S.L. (2018) Subglacial water storage and drainage beneath the Fennoscandian and Barents Sea ice sheets. Quaternary Science Reviews, 201, 13–28, https://doi.org/10.1016/j.quascirev.2018.10.007 (pdf)

Kingslake, J., R.P. Scherer, T. Albrecht, J. Coenen, R.D. Powell, R. Reese, N.D. Stansell, S. Tulaczyk, M.G. Wearing & P.L. Whitehouse (2018) Extensive retreat and re-advance of the West Antarctic Ice Sheet during the Holocene. Nature, 558(7710), 430–434. (pdf)

Kingslake, J., J.C. Ely, I. Das, & R.E. Bell (2017) Widespread movement of meltwater onto and across Antarctic ice shelves. Nature, 544(7650), 349-352. (pdf)

Bell, R.E., W. Chu, J. Kingslake, I. Das, M. Tedesco, K.J. Tinto, C.J. Zappa, M. Frezzotti, A. Boghosian & W.S. Lee (2017) Antarctic ice shelf potentially stabilized by export of meltwater in surface river. Nature, 544(7650), 344-348. (pdf)

Livingstone, S.J. , W. Chu, J.C. Ely & J. Kingslake (2017) Palaeofluvial and subglacial channel networks beneath Humboldt Glacier, Greenland. Geology, G38860-1. (pdf)

Kingslake, J., C. Martín, R.J. Arthern, H.F.J. Corr & E.C. King. (2016) Ice-flow reorganization in West Antarctica 2.5 kyr ago dated using radar-derived englacial flow velocities. Geophys. Res. Lett. 43, https://doi.org/10.1002/2016GL070278. (pdf)

Matsuoka, K. & 19 others (including J. Kingslake) (2015) Antarctic ice rises and rumples: their properties and significance for ice-sheet dynamics and evolution. Earth Sci. Rev., 150, 724-745. (pdf)

Evatt, W.E, D. Abrahams, M. Heil, C. Mayer, J. Kingslake, S.L. Mitchell, A.C. Fowler & C.D. Clark (2015) Glacial melt under a porous debris layer. J. Glaciol., 61(229), 825-836. (pdf)

Kingslake, J. (2015) Chaotic dynamics of a glaciohydraulic model. J. Glaciol., 61(227), 493. (pdf)

Kingslake, J., F. Ng & A. Sole (2015) Modelling channelized surface drainage of supraglacial lakes. J. Glaciol., 61(225), 185-199. (pdf)

Kingslake, J., R.C.H. Hindmarsh, G. Aðalgeirsdóttir, H. Conway, H.F.J. Corr, F. Gillet-Chaulet, C. Martín, E.C. King, R. Mulvaney & H.D. Pritchard. (2014) Full-depth englacial vertical ice-sheet velocities measured using phase-sensitive radar. J. Geophys. Res. Earth Surf., 119, 2604–2618. (pdf)

Livingstone, S.J., C.D. Clark, J. Woodward & J. Kingslake (2013) Potential subglacial lake locations and meltwater drainage pathways beneath the Antarctic and Greenland ice sheets. Cryosphere, 7(6), 1721-1740. (pdf)

Siegert, M., N. Ross, H.F.J. Corr, J. Kingslake & R.C.H. Hindmarsh (2013) Late Holocene ice-flow reconfiguration in the Weddell Sea sector of West Antarctica. Quat. Sci. Rev., 78, 98-107. (pdf)

Kingslake, J. and F. Ng (2013) Quantifying the predictability of the timing of jökulhlaups from Merzbacher Lake, Kyrgyzstan. J. Glaciol., 59(217), 805-818. (pdf)

Kingslake, J. and F. Ng (2013) Modelling the coupling of flood discharge with glacier flow during jökulhlaups. Ann. Glaciol., 54(63), 25-31. (pdf)

Jonny Kingslake – Glaciologist