scholarly journals Tsunami deposits in Martinique related to the 1755 Lisbon earthquake

2017 ◽  
Author(s):  
Valérie Clouard ◽  
Jean Roger ◽  
Emmanuel Moizan
Keyword(s):  
Collaborative Research ◽  
Time Window ◽  
Oceanic Islands ◽  
Recurrence Time ◽  
Tsunami Deposit ◽  
Archaeological Remains ◽  
Tropical Islands ◽  
Tsunami Inundation ◽  
Lisbon Earthquake ◽  
Drainage Channels

Abstract. In order to assess tsunami hazard in oceanic islands, one needs to enlarge the observational time window by finding more evidence of past events. To that end, evidence of allochthonous deposits provides estimates of tsunami inundation, recurrence time and magnitude. However, in tropical islands, erosion due to the highly rainy climate generally prevents deposits to stay in place and when they are, relating them to a tsunami is not straightforward, as they can result either from a strong hurricane or from a tsunami. One notable exception concerns deposits sealed by subsequent events. In this paper, we present evidence of an anomalously thick two-layer tsunami deposit in an excavation in Martinique. Analysis of the archaeological remains indicate that it is related to the 1755 Lisbon tsunami. We explain the thickness of the deposit by a tsunami-induced bore in the mangrove drainage channels of Fort-de-France. Our results highlight the benefits of collaborative research involving geology and archaeology, indicate a way to improve our tsunami databases and further constrain the use of numerical modelling to predict paleo-tsunami deposit thickness.

scholarly journals A Possible Tsunami Deposit Associated to the CE 1755 Lisbon Earthquake on the Western Coast of Portugal

Geosciences ◽  
2020 ◽  
Vol 10 (7) ◽  
pp. 257 ◽  
Author(s):  
Mihaela Tudor ◽  
Ana Ramos-Pereira ◽  
Pedro J.M. Costa
Keyword(s):  
Western Coast ◽  
Tsunami Deposit ◽  
Spatial Presence ◽  
Tsunami Inundation ◽  
Quantitative Classification ◽  
Physical Evidence ◽  
Historical Tsunami ◽  
Lisbon Earthquake ◽  
Sandy Layer ◽  
Innovative Work

The CE 1755 Lisbon tsunami was the largest historical tsunami to affect the Atlantic coasts of Europe and North Africa. This study presents the results obtained from the application of different sedimentological techniques (e.g., grain size, morphoscopy, microtextural analysis, geochemistry, radiocarbon dating) on sediments retrieved from the Alcabrichel River alluvial plain (of about 500 m far away from its mouth and approximatively 50 km northwest of Lisbon, Portugal). The results allowed the identification of a sandy layer that was associated with the CE 1755 tsunami. Furthermore, a new microtextural semi-quantitative classification was applied to enhance the identification of extreme marine inundation deposits. Based on sedimentological data, three different tsunami inundation phases were identified, including two inundations and a likely backwash. This innovative work offers physical evidence of the spatial presence of the CE 1755 tsunami event on the western coast of Europe. It also enables a reconstruction of tsunami inundation dynamics, with two flooding waves and an interspersed backwash.

scholarly journals Recurrence time distribution and temporal clustering properties of a cellular automaton modelling landslide events

2013 ◽  
Vol 20 (6) ◽  
pp. 1071-1078 ◽  
Author(s):  
E. Piegari ◽  
R. Di Maio ◽  
A. Avella
Keyword(s):  
Time Series ◽  
Probability Distribution ◽  
Cellular Automaton ◽  
Time Window ◽  
Fano Factor ◽  
Recent Analysis ◽  
Recurrence Time ◽  
Model Parameters ◽  
Reasonable Prediction ◽  
First Time

Abstract. Reasonable prediction of landslide occurrences in a given area requires the choice of an appropriate probability distribution of recurrence time intervals. Although landslides are widespread and frequent in many parts of the world, complete databases of landslide occurrences over large periods are missing and often such natural disasters are treated as processes uncorrelated in time and, therefore, Poisson distributed. In this paper, we examine the recurrence time statistics of landslide events simulated by a cellular automaton model that reproduces well the actual frequency-size statistics of landslide catalogues. The complex time series are analysed by varying both the threshold above which the time between events is recorded and the values of the key model parameters. The synthetic recurrence time probability distribution is shown to be strongly dependent on the rate at which instability is approached, providing a smooth crossover from a power-law regime to a Weibull regime. Moreover, a Fano factor analysis shows a clear indication of different degrees of correlation in landslide time series. Such a finding supports, at least in part, a recent analysis performed for the first time of an historical landslide time series over a time window of fifty years.

scholarly journals Remoteness promotes biological invasions on islands worldwide

2018 ◽  
Vol 115 (37) ◽  
pp. 9270-9275 ◽  
Author(s):  
Dietmar Moser ◽  
Bernd Lenzner ◽  
Patrick Weigelt ◽  
Wayne Dawson ◽  
Holger Kreft ◽  
...  
Keyword(s):  
Alien Species ◽  
Island Biogeography ◽  
Native Species ◽  
Native Plants ◽  
Oceanic Islands ◽  
Tropical Islands ◽  
Large Dataset ◽  
Island Species ◽  
Species Pools ◽  
Natural Dispersal

One of the best-known general patterns in island biogeography is the species–isolation relationship (SIR), a decrease in the number of native species with increasing island isolation that is linked to lower rates of natural dispersal and colonization on remote oceanic islands. However, during recent centuries, the anthropogenic introduction of alien species has increasingly gained importance and altered the composition and richness of island species pools. We analyzed a large dataset for alien and native plants, ants, reptiles, mammals, and birds on 257 (sub) tropical islands, and showed that, except for birds, the number of naturalized alien species increases with isolation for all taxa, a pattern that is opposite to the negative SIR of native species. We argue that the reversal of the SIR for alien species is driven by an increase in island invasibility due to reduced diversity and increased ecological naiveté of native biota on the more remote islands.

Real-Time Tsunami Inundation Forecast for a Recurrence of 17thCentury Great Hokkaido Earthquake in Japan

2014 ◽  
Vol 9 (3) ◽  
pp. 358-364 ◽  
Author(s):  
Yuichiro Tanioka ◽  
◽  
Aditya Riadi Gusman ◽  
Kei Ioki ◽  
Yugo Nakamura
Keyword(s):  
Real Time ◽  
Pacific Coast ◽  
Great Earthquake ◽  
Tsunami Deposit ◽  
Fault Models ◽  
Fine Grid ◽  
Tsunami Inundation ◽  
Inundation Area ◽  
The Pacific ◽  
Tsunami Waveforms

Paleotsunami studies have shown that several large tsunamis hit the Pacific coast. Many tsunami deposit data were available for the 17thcentury tsunami. The most recent tsunami deposit study in 2013 indicated that the large slip of about 25 m along the plate interface near the Kurile trench would be necessary and the seismic moment of this 17thcentury earthquake was 1.7 × 1022Nm. If a great earthquake like the 17thcentury earthquake occurs off the Pacific coast of Hokkaido, the devastating disaster along the coast is expected. To minimize the tsunami disaster, a development of the real-time forecast of a tsunami inundation area is necessary. Estimating a tsunami inundation area requires tsunami numerical simulation with a very fine grid system of less than 1 arcsecond. There is not enough time to compute the tsunami inundation area after a large earthquake occurs. In this study, we develop a real-time tsunami inundation forecast method using a database including many tsunami inundation areas previously computed using various fault models. After great earthquakes, tsunamis are computed using linear long-wave equations for fault models estimated in real time. Simulating such tsunamis takes only 1-3 minutes on a typical PC, so it is potentially useful for forecasting tsunamis. Tsunami inundation areas computed numerically using various fault models and tsunami waveforms at several locations near the inundation area are stored in a database. Those computed tsunami waveforms are used to choose the most appropriate tsunami inundation area by comparing them to the tsunami waveforms computed in real time. This method is tested at Kushiro, a city in Hokkaido. We found that the method worked well enough to forecast the Kushiro’s tsunami inundation area.

Two Creeks Interstade Dated through Dendrochronology and AMS

1994 ◽  
Vol 42 (3) ◽  
pp. 288-298 ◽  
Author(s):  
Klaus Felix Kaiser
Keyword(s):  
Lake Michigan ◽  
Time Window ◽  
Northern Europe ◽  
Tree Ring Chronology ◽  
The North ◽  
Dendrochronological Analysis ◽  
Drainage Channels ◽  
Western Shore ◽  
Indian River ◽  
Straits Of Mackinac

AbstractDendrochronological analysis of fossil wood from Two Creeks, Wisconsin, reveals that the Two Creekan Intetstade lasted at least 252 yr. The sites crossdated by tree rings cover an area of about 970 km2. AMS determinations from the beginning and end of the chronology open a 14 C time window for the episode from 12,050 to 11,750 yr B.P. The interval is contemporaneous with the Older Dryas in northern Europe. The development of a forest covering at least 970 km2 on the western shore of Lake Michigan indicates a water level about as low as in modern times. Glacier retreat must have opened drainage channels either through the Straits of Mackinac or via the Indian River Plateau into the eastern lakes. The beginning of the tree-ring chronology coincides with the peak of meltwater pulse 1A at 12,000 yr B.P. Increased amounts of meltwater seem to have disturbed the heat exchange between the waters and the atmosphere in the North Atlantic off the Gulf of St. Lawrence or affected the δ18O-ratio of the evaporation, causing the climatic or isotopic reversal of the Older Dryas in Greenland and northern Europe.

scholarly journals Depth diversity profile of polychaete worms in Bahía Chatham, Isla del Coco National Park, Costa Rican Pacific

2017 ◽  
pp. 303-319
Author(s):  
Jeffrey A. Sibaja-Cordero ◽  
Jorge Cortés ◽  
Harlan K. Dean
Keyword(s):  
Costa Rica ◽  
National Park ◽  
Oceanic Islands ◽  
Costa Rican ◽  
Depth Gradient ◽  
Tropical Islands ◽  
Ecological Features ◽  
Diversity Profile ◽  
Species Being ◽  
Sand Bottom

The subtidal benthos of tropical islands has been poorly studied in the Eastern Tropical Pacific. Several studies have been published on taxonomic collections from oceanic islands in the region, but ecological features and community structure are practically unknown. In the present study, composition of the polychaete community along a depth gradient from the sand bottom of Bahía Chatham, Isla del Coco National Park, Costa Rica is analyzed. Fifty species of polychaetes belonging to 28 families were found. There is a peak in diversity, abundance and richness at 28-30m. The lowest values occurred at 50m depth with values increasing below this depth. The composition of species changed with depth with some species being found only at depths either less than or greater than 50m. This pattern can be explained in part by the location of the thermocline that occurred at around 50m depth. Citation: Sibaja-Cordero, J.A., J. Cortés & H.K. Dean. 2012. Depth diversity profile of polychates worms in Bahía Chatham, Isla del Coco National Park, Pacific of Costa Rica. Rev. Biol. Trop. 60 (Suppl. 3): 293-301. Epub 2012 Dec 01.

scholarly journals Tracing woody-organic tsunami deposits of the 2011 Tohoku-oki event in Misawa (Japan)

2021 ◽  
Vol 11 (1) ◽  
Author(s):  
Piero Bellanova ◽  
Mike Frenken ◽  
Yuichi Nishimura ◽  
Jan Schwarzbauer ◽  
Klaus Reicherter
Keyword(s):  
Analytical Data ◽  
Control Area ◽  
Organic Layer ◽  
Sandy Sediment ◽  
Tsunami Deposit ◽  
Organic Fraction ◽  
Tsunami Deposits ◽  
Tsunami Inundation ◽  
Sandy Deposit ◽  
Sand Sheets

AbstractWith a minimum of three reported waves, the 2011 Tohoku-oki tsunami’s destructive force caused massive damage along the northern Japanese Aomori coast. At Misawa the coastal control area was inundated up to 550 m inland and sandy sediment remnants can be traced to c. 350 m (c. 61–63% of the maximum inundation) from the shoreline. Linking the discovery of floatable plastic objects within a woody and organic layer to our analytical data lead to the detection of a yet undocumented woody-organic tsunami deposit first appearing on top of the sandy deposit but then reaching even further inland (approx. 69–72% of the max. inundation). By this observation our understanding of the documented part of the tsunami inundation may be improved. As a consequence, sand sheets of historic and paleo-tsunamis represent minimum estimates for the coastal inundation and underestimation may be reduced by addressing the woody and organic fraction of a tsunami’s inundation.

Feel Thine Own Self – Mood Congruency Evaluation of Emotional State Adjectives

2020 ◽  
pp. 1-17
Author(s):  
Szczepan J. Grzybowski ◽  
Miroslaw Wyczesany ◽  
Jan Kaiser
Keyword(s):  
Mood Induction ◽  
Semantic Analysis ◽  
Emotional State ◽  
Time Window ◽  
Event Related Potential ◽  
Negativity Bias ◽  
Positive Potential ◽  
Semantic Access ◽  
Current Mood ◽  
Component Time

Abstract. The goal of the study was to explore event-related potential (ERP) differences during the processing of emotional adjectives that were evaluated as congruent or incongruent with the current mood. We hypothesized that the first effects of congruence evaluation would be evidenced during the earliest stages of semantic analysis. Sixty mood adjectives were presented separately for 1,000 ms each during two sessions of mood induction. After each presentation, participants evaluated to what extent the word described their mood. The results pointed to incongruence marking of adjective’s meaning with current mood during early attention orientation and semantic access stages (the P150 component time window). This was followed by enhanced processing of congruent words at later stages. As a secondary goal the study also explored word valence effects and their relation to congruence evaluation. In this regard, no significant effects were observed on the ERPs; however, a negativity bias (enhanced responses to negative adjectives) was noted on the behavioral data (RTs), which could correspond to the small differences traced on the late positive potential.

Time Window from Visual Images to Visual Short-Term Memory: Consolidation or Integration?

2004 ◽  
Vol 51 (1) ◽  
pp. 45-51 ◽  
Author(s):  
Yuhong Jiang
Keyword(s):  
Short Term Memory ◽  
Time Window ◽  
Short Interval ◽  
Visual Images ◽  
Short Term ◽  
Temporal Window ◽  
Term Memory ◽  
Visual Short Term Memory ◽  
Probe Task ◽  
Long Time

Abstract. When two dot arrays are briefly presented, separated by a short interval of time, visual short-term memory of the first array is disrupted if the interval between arrays is shorter than 1300-1500 ms ( Brockmole, Wang, & Irwin, 2002 ). Here we investigated whether such a time window was triggered by the necessity to integrate arrays. Using a probe task we removed the need for integration but retained the requirement to represent the images. We found that a long time window was needed for performance to reach asymptote even when integration across images was not required. Furthermore, such window was lengthened if subjects had to remember the locations of the second array, but not if they only conducted a visual search among it. We suggest that a temporal window is required for consolidation of the first array, which is vulnerable to disruption by subsequent images that also need to be memorized.

Sign in / Sign up

Export Citation Format

Share Document