title: Benthic foraminiferal response to changes in bottom-water oxygenation and organic carbon flux in the eastern Mediterranean during LGM to Recent times

authors: Abu-Zied, Ramadan H.

subjects: benthic foraminifera

abstract: We present a high-resolution study of benthic foraminiferal abundances in 4 cores from the central Aegean and NE Levantine Seas, spanning the interval from 30 ka BP to the present. The benthic foraminiferal faunas indicate that during LGM times, bottom waters were well ventilated, while organic flux to the sea floor was significantly higher than today. From 30 to 10.2 ka BP, faunal density and composition suggest a gradual decrease in organic flux to the sea floor. This trend is interrupted by a short return to higher organic flux levels during the Younger Dryas (12.8–11.5 ka BP). The faunas immediately preceding the early to middle Holocene organic-rich layer (sapropel) S1 are very similar to Late Holocene faunas, indicating oligotrophic conditions. The transition from well ventilated bottom waters to anoxic (Levantine Basin) or strongly dysoxic (Aegean Sea) bottom waters appears to take place within a time-span of only 600 years, from ∼ 10.8 to 10.2 ka BP. Sapropel S1 (10.2–6.4 ka BP) is characterized by extended periods of bottom-water anoxia in the Levantine Basin, and by strongly dysoxic conditions punctuated by episodic re-ventilation events in the Aegean Sea. Re-establishment of fully oxygenated bottom-water conditions after sapropel S1 was extremely rapid. The ensuing Late Holocene faunas are very similar to recent faunas found in the Aegean Sea, suggesting much lower fluxes of organic matter to the sea floor than during glacial times.

text: Benthic foraminiferal response to changes in bottom-water oxygenation and organic carbon flux in the eastern Mediterranean during LGM to Recent times We present a high-resolution study of benthic foraminiferal abundances in 4 cores from the central Aegean and NE Levantine Seas, spanning the interval from 30 ka BP to the present. The benthic foraminiferal faunas indicate that during LGM times, bottom waters were well ventilated, while organic flux to the sea floor was significantly higher than today. From 30 to 10.2 ka BP, faunal density and composition suggest a gradual decrease in organic flux to the sea floor. This trend is interrupted by a short return to higher organic flux levels during the Younger Dryas (12.8–11.5 ka BP). The faunas immediately preceding the early to middle Holocene organic-rich layer (sapropel) S1 are very similar to Late Holocene faunas, indicating oligotrophic conditions. The transition from well ventilated bottom waters to anoxic (Levantine Basin) or strongly dysoxic (Aegean Sea) bottom waters appears to take place within a time-span of only 600 years, from ∼ 10.8 to 10.2 ka BP. Sapropel S1 (10.2–6.4 ka BP) is characterized by extended periods of bottom-water anoxia in the Levantine Basin, and by strongly dysoxic conditions punctuated by episodic re-ventilation events in the Aegean Sea. Re-establishment of fully oxygenated bottom-water conditions after sapropel S1 was extremely rapid. The ensuing Late Holocene faunas are very similar to recent faunas found in the Aegean Sea, suggesting much lower fluxes of organic matter to the sea floor than during glacial times.

year: 2008

title: The role of control in risk perception on rural roads

authors: Starkey, Nicola J.

subjects: Illusion of control

abstract: Risk perception plays an important role in driver behaviour, particularly for speed choice. Risk perception studies use a range of techniques from on-road data collection to ratings of still photos, however participants’ratings differ depending on the study methodology, possibly due to their perception of control. To explore this we conducted a multiple methods study to investigate drivers’perceptions of risk on rural roads. One group of participants drove (Drivers, n = 13) a 180 km route along rural roads (accompanied by a research assistant) and provided verbal risk ratings at thirteen locations of interest. A second group (Passengers, n = 10) provided ratings at the same points when travelling as a passenger in a vehicle (driven by a research assistant). The third group (Observers, n = 14) were shown videos of the same rural roads (filmed from the drivers’perspective) and also provided risk ratings at the same locations. A week later participants were invited to the laboratory to review the video footage and comment on factors that contributed to the risk ratings. Overall, the Observers gave the highest risk ratings and Drivers the lowest. The Observers also provided twice the number of comments to justify their risk rating compared to the other two groups. The results suggest that control, and on-road experience play a significant role in how perceptions of driving risk are formed and the degree of risk experienced.These findings also bring into question the accuracy of using video-based tasks to assess drivers’ risk perception (and speed choice), particularly if the findings are used to inform on-road safety interventions.

text: The role of control in risk perception on rural roads Risk perception plays an important role in driver behaviour, particularly for speed choice. Risk perception studies use a range of techniques from on-road data collection to ratings of still photos, however participants’ratings differ depending on the study methodology, possibly due to their perception of control. To explore this we conducted a multiple methods study to investigate drivers’perceptions of risk on rural roads. One group of participants drove (Drivers, n = 13) a 180 km route along rural roads (accompanied by a research assistant) and provided verbal risk ratings at thirteen locations of interest. A second group (Passengers, n = 10) provided ratings at the same points when travelling as a passenger in a vehicle (driven by a research assistant). The third group (Observers, n = 14) were shown videos of the same rural roads (filmed from the drivers’perspective) and also provided risk ratings at the same locations. A week later participants were invited to the laboratory to review the video footage and comment on factors that contributed to the risk ratings. Overall, the Observers gave the highest risk ratings and Drivers the lowest. The Observers also provided twice the number of comments to justify their risk rating compared to the other two groups. The results suggest that control, and on-road experience play a significant role in how perceptions of driving risk are formed and the degree of risk experienced.These findings also bring into question the accuracy of using video-based tasks to assess drivers’ risk perception (and speed choice), particularly if the findings are used to inform on-road safety interventions.

year: 2020

title: Hostile shores: catastrophic events in prehistoric New Zealand and their impact on Maori coastal communities [Book Review]

authors: Lowe, David J.

abstract: This article reviews the book: “Hostile shores: catastrophic events in prehistoric New Zealand and their impact on Maori coastal communities”, by Bruct McFadgen.

text: Hostile shores: catastrophic events in prehistoric New Zealand and their impact on Maori coastal communities [Book Review] This article reviews the book: “Hostile shores: catastrophic events in prehistoric New Zealand and their impact on Maori coastal communities”, by Bruct McFadgen.

year: 2008