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- Simkins, Lauren M., et al.
(författare)
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Advances in understanding subglacial meltwater drainage from past ice sheets
- 2022
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Ingår i: Annals of Glaciology. - 0260-3055 .- 1727-5644. ; 63:87-89, s. 83-87
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Tidskriftsartikel (refereegranskat)abstract
- Meltwater drainage beneath ice sheets is a fundamental consideration for understanding ice–bed conditions and bed-modulated ice flow, with potential impacts on terminus behavior and ice-shelf mass balance. While contemporary observations reveal the presence of basal water movement in the subglacial environment and inferred styles of drainage, the geological record of former ice sheets, including sediments and landforms on land and the seafloor, aids in understanding the spatiotemporal evolution of efficient and inefficient drainage systems and their impact on ice-sheet behavior. We highlight the past decade of advances in geological studies that focus on providing process-based information on subglacial hydrology of ice sheets, how these studies inform theory, numerical models and contemporary observations, and address the needs for future research.
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| 3. |
- Lepp, Allison P., et al.
(författare)
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Insights into glacial processes from micromorphology of silt-sized sediment
- 2024
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Ingår i: The Cryosphere. - 1994-0416 .- 1994-0424. ; 18:5, s. 2297-2319
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Tidskriftsartikel (refereegranskat)abstract
- Silt-rich meltwater plume deposits (MPDs) analyzed from marine sediment cores have elucidated relationships that are clearly connected, yet difficult to constrain, between subglacial hydrology, ice-marginal landforms, and grounding-zone retreat patterns for several glacial catchments. Few attempts have been made to infer details of subglacial hydrology, such as flow regime, geometry of drainage pathways, and mode(s) of sediment transport through time, from grain-scale characteristics of MPDs. Using sediment samples from MPD, till, and grounding-zone proximal diamicton collected offshore of six modern and relict glacial catchments in both hemispheres, we examine grain shape distributions and microtextures (collectively, grain micromorphology) of the silt fraction to explore whether grains are measurably altered from their subglacial sources via meltwater action. We find that 75 % of all imaged grains (n = 9400) can be described by 25 % of the full range of measured shape morphometrics, indicating grain shape homogenization through widespread and efficient abrasive processes in subglacial environments. Although silt grains from MPDs exhibit edge rounding more often than silt grains from tills, grain surface textures indicative of fluvial transport (e.g., v-shaped percussions) occur in only a modest number of grains. Furthermore, MPD grain surfaces retain several textures consistent with transport beneath glacial ice (e.g., straight or arcuate steps, (sub)linear fractures) in comparable abundances to till grains. Significant grain shape alteration in MPDs compared to their till sources is observed in sediments from glacial regions where (1) high-magnitude, potentially catastrophic meltwater drainage events are inferred from marine sediment records and (2) submarine landforms suggest supraglacial melt contributed to the subglacial hydrological budget. This implies that quantifiable grain shape alteration in MPDs could reflect a combination of high-energy flow of subglacial meltwater, persistent sediment entrainment, and/or long sediment transport distances through subglacial drainage pathways. Integrating grain micromorphology into analysis of MPDs in site-specific studies could therefore aid in distinguishing periods of persistent, well-connected subglacial discharge from periods of sluggish or disorganized drainage. In the wider context of deglacial marine sedimentary and bathymetric records, a grain micromorphological approach may bolster our ability to characterize ice response to subglacial meltwater transmission through time. This work additionally demonstrates that glacial and fluvial surface textures are retained on silt-sized quartz grains in adequate amounts for microtexture analysis, which has heretofore been conducted exclusively on the sand fraction. Therefore, grain microtextures can be examined on silt-rich glaciogenic deposits that contain little to no sand as a means to evaluate sediment transport processes.
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| 5. |
- Wigert, Helena, 1960, et al.
(författare)
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Managing conflict situations nursing students encounter during their clinical practice, narrated and performed through Forum Play
- 2021
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Ingår i: Nurse Education in Practice. - : Elsevier BV. - 1471-5953 .- 1873-5223. ; 56
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Tidskriftsartikel (refereegranskat)abstract
- Aim: To describe and illuminate conflict situations nursing students encounter during their clinical practice, narrated and performed through Forum Play. Background: Conflicts are common in healthcare settings and affect patient care and the wellbeing of nurses. To be able to manage complex practice situations, conflict management is an essential competence for nurses and should be highlighted during education. The aim of the study was to describe and illuminate conflict situations nursing students encounter during their clinical practice, narrated and performed through Forum Play. Design: The study was designed as a summative qualitative analysis of written group assignments related to nursing students' participation in a drama workshop. Method: A summative qualitative content analysis of written group assignments related to nursing students' participation in a drama workshop, focusing on conflict management. During the workshop the students explored conflict situations they had encountered during clinical practice, through Forum Play. After the workshop, the students handed in a mandatory written group assignment where they described one of the conflict situations. Results: The findings are presented in three categories; Parties; Arenas; Situations, one main theme; "Who knows best" and two subthemes; Difficulties to adapt to the new and Difficulties reaching a mutual understanding. Conclusion: Conflict situations that nursing students encounter during their clinical practice often stem from the health care staff's difficulties in adapting to the new and difficulty reaching a mutual understanding. Conflict management can be implemented as a powerful learning strategy in nursing education.
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