When the Oso landslide engulfed a neighborhood along the North Fork of the Stillaguamish River last year, its size and ferocity were stunning even to geologists. But a new analysis shows that the deadliest landslide in U. But a new analysis from the University of Washington makes it clear that the deadliest landslide in U. In fact, the researchers estimate that over the past 2, years, the same stretch of valley has been slammed by a major slide every years, on average. After the March 22, , disaster, which killed 43 people, geologists reviewed maps of the area based on a laser scanning technique called lidar. By stripping away vegetation, the lidar revealed tracks left by large, past landslides up and down the valley. But it was impossible to tell how long ago those slides occurred. If they were truly ancient — dating back to soon after the last ice age — then the Oso slide might have been just an outlier, and not representative of the present-day hazard, explained UW geologist and co-author Alison Duvall. The researchers set out to answer that question by determining the dates of more than two dozen major slides along a 3.
Dating of landslides around Oso reveals recurring patterns
William T. Struble, Joshua J. Roering, Bryan A.
Based on a review of > dated landslides throughout the world, this paper aims to outline advances in landslide dating since the beginning of the new.
Colin K. Sandeman, Sheng Xu. Little is known of hard-rock coastal landsliding in Scotland. Thirty-one sites exhibit evidence of at least localized recent activity. Analysis of 16 landslides on Fetlar NE Shetland indicates that most are translational dip-slip failures; 3 represent deep-seated failures and several exhibit active frontal erosion attributable to basal sapping by storm waves.
As these landslides terminate in shallow water, failure was probably initiated when rising sea level resulted in footslope erosion and upslope propagation of instability, causing downslope displacement of landslide blocks on upper slopes. Our results suggest that landslides have played a hitherto undocumented but important role in retreat of cliffed coastlines in Scotland.
Dawson, S. Natural Environment Research Council. Project : Research. The coastal landslides of Shetland. N2 – Little is known of hard-rock coastal landsliding in Scotland.
Dating Landslides with Trees
The Blackhawk landslide is best known as an example to support a number of hypotheses regarding large volume landslide mechanics. Surprisingly, there is little dating control on the timing of the landslide. This page briefly outlines our approach to determine the timing of landsliding by using surface exposure age dating. The Blackhawk landslide is a granular slide that sourced in the San Bernardino Mountains.
landslide dating techniques as well as landslide susceptibility modeling protocols used elsewhere in the world. Landslides in KZN were also identified from.
With a wave runup of nearly metres, the tsunami that ripped through an Alaskan fjord in was one of the largest ever documented. But with no-one killed, it almost went unnoticed. The tsunami generated a wave runup, the maximum vertical extent of wave uprush on a beach, of metres feet. Glacial ice supports and undercuts steep slopes so when the ice melts, the underlying bedrock is left exposed and unstable, increasing the likelihood of rockfalls and landslides.
Most of the recent risk research on tsunamis has focused on those caused by earthquakes, such as one in the Indian Ocean in Little is known about landslide tsunamis, which are relatively rare, with the best-documented example dating back 60 years. As well as being rare, such events tend to occur in remote, dangerous locations and the traces of geological evidence left behind tend to get quickly covered up. This time, experts were able to capture high quality satellite footage and other data before the slide that showed how the ground was cracking and shifting as the glacier retreated.
Crucially, they were also able to get a detailed picture of the distinct sedimentary record left by the tsunami that could shed light on earlier incidents and also provide clues to predict future risks.
Dating historic activity at Oso site shows recurring major landslides
Official websites use. Share sensitive information only on official, secure websites. Stratigraphic constraints on the timing and emplacement of the Alika 2 giant Hawaiian submarine landslide Journal of Volcanology and Geothermal Research.
Figure Relative age classes of pre landslides in the The date that the Oso Landslide occurred is noted with a red arrow and date;.
Washington football coach Jimmy Lake spoke to the media on Friday for the first time since the Pac Conference announced the postponement of the fall sports season. Rather than reviews, articles cover topics from each book that are particularly relevant to college students and Seattle life, with input from professors and UW communit….
A team of UW researchers in mechanical engineering and electrical engineering has developed a tiny, steerable wireless camera about the size of a penny. His study reveals a major slide happened around years ago around the area in the journal Geology. After a hillside near the town of Oso, Wash. They knew the Oso valley had historically seen many landslides, but exactly when had they happened? And when would the next one strike?
Some answers, it turned out, were buried deep in the very same hill that had collapsed.
Jump to navigation. From We Proceeded On 1. J ohn Jengo is a professional geologist and licensed Site Remediation Professional who works for an environmental consulting firm in Pennsylvania, specializing in hydrocarbon remediation and dam removals to restore migratory fish passage.
This page briefly outlines our approach to determine the timing of landsliding by using surface exposure age dating. The Blackhawk landslide is a granular slide.
Tree Rings and Natural Hazards pp Cite as. Dendrochronology is increasingly being use in natural hazard studies, especially in those concerned with estimating risk. Central to such studies are frequency—magnitude relations, which relate the size of hazardous events to their average recurrence. Frequency—magnitude curves are best established from observational data, but the historic record may be too brief to capture extreme events, or it may be otherwise non-representative of longer periods.
Earth scientists thus use the recent geologic record to add depth to the observational database by estimating both the size distribution of prehistoric events and the frequency of events of different size. The latter requires knowledge of the ages of prehistoric events, which is where dendrochronology comes into play. Some past earthquakes, landslides, floods, and other events can be dated using tree rings and the ages then used to quantify relations between event frequency and magnitude.
The equations that define frequency—magnitude relations, in turn, are the basis for probability-based forecasts of hazard.
Landslide 21 Million Years Ago Rivals Largest Known
Metrics details. This study examined the frequency-size distribution of landslides spread over km 2 in Iburi Subprefecture, Hokkaido, Japan, induced by the Hokkaido Eastern Iburi Earthquake M w 6. The study area is characterized by gently undulating terrain that is finely dissected by shallow streams and covered predominantly by layers of volcanic products with high water content.
Low ridges separating small catchments allowed individual landslides to coalesce in many locations.
dating of movement episodes and periods of dormancy. The age of graben-fill sediments in the head of the landslide (>29, 14C yr B.P.) indicates that the.
Most of us have seen splotchy lichens clinging to rocks, trees and maybe even the ground, but did you know that you can date landslides with lichens? Lichens grow only. This technique has been used to date historic earthquakes that may have caused landslides. While lichens are a relatively new tool in geologic applications, there have been numerous uses of lichens by humans for centuries. Ethnolichenology is the study of how humans have used lichens in making dyes, in medicine and even as a food.
The use of lichens in traditional medicine is extensive in many cultures. There are numerous examples of how traditional Chinese and Indian medicine capitalize on some varieties to treat a multitude of illnesses. Other folk medicines have used lichens for cold, arthritis, fever, cough, and even tuberculosis among other ailments. Not all lichens are beneficial, though, and just as one has to be careful with eating hand-picked mushrooms, you also have to known your lichens.
More recently, lichens are indicators of climate change and air pollution. Your email address will not be published. Skip to content. February 1, February 19, Mike K.
Paleoseismology, Volume 62
Large-scale landslides, especially those that block rivers, are among the most dangerous natural phenomena in mountainous regions all over the world. Occurrence of the world’s biggest landslide in the Kabirkuh and on the way of Seymareh and Kashkan rivers blocked rivers and formed Seymareh and Jaydar dam lakes. The aim of this research which is an applied-developmental research and which is conducted using observational, historical and analytical methods is to reconstruct the dam lakes caused by Seymareh landslide occurrence and also to determine the age of them utilizing thermo luminescence techniques in order to determine the date of the occurrence of Seymareh landslide and formation of the lakes.
Field studies using physical and conceptual tools together with laboratory methods have led to recognize four staged stalactites slips in the Kabirkuh and the subsequent formation of four lakes in the area of Seymareh valley and a single-stage lake within the Kashkan valley. The findings based on dating of eight samples from the surface and floor of Seymareh and Jaydar lakes using Thermo luminescence shows that the occurrence date of the Seymareh landslide and primary formation of of Seymareh lake is years ago.
The second Seymareh Lake formed years ago, the third one formed years ago and the fourth lake formed years ago.
Dated landslides in the plate interiors are lacking, especially in South America, Africa and Australia. Despite the fact that some dating results.
The purpose of this study is to explore and illustrate the potential of exposed roots to reconstruct larger-scale landslide activity and thus to complement tree-ring data gathered from stems to reconstruct spatio-temporal patterns of landslide reactivation. The study demonstrates that reconstructions of landslide reactivations obtained from exposed roots samples are not significantly different from those gathered from stems, but that the inclusion of exposed roots permits realization of frequency maps in sectors which could not be documented with classic dendrogeomorphic approaches focusing on tree-ring records from stems scars, cracks.
In addition, and even more importantly, the inclusion of exposed roots allowed assessment of the geomorphic evolution of the landslide at the local scale and to detect precursor signals of major reactivations in the form of crack widening before the main movement was registered in the tree stems. In that sense, the combined approach presented in this paper can be considered as a valuable tool for land-use planners and emergency cells in charge of forecasting future events and in protecting people and their assets from the negative effects of landslides.
As a consequence, their occurrence has recently become a topic of major interest for both researchers and local administrators, especially in terms of landslide hazard and risk assessments Magliulo et al. The steadily growing interest in landslides certainly reflects the increasing awareness of the socio-economic significance of the process Aleotti and Chowdhury, but also indicates quite clearly that human pressure on the environment is becoming ever more important for land development and urbanization Petrascheck and Kienholz, An appropriate assessment of existing and potential future landslide hazards becomes a prerequisite for a sustainable land-use, but requires, among others, a detailed determination of the spatial and temporal occurrences of landslides at the site level.
However, major obstacles normally exist to obtain this kind of data, mainly due to the lack of reliable historical records on the frequency and localization of past events Aleotti and Chowdhury, As a consequence, past research on landslides focused more on their susceptibility see Guzzetti, , and references therein for a review rather than on the documentation of landslide hazards at the level of individual sites.
As trees suffering from superficial and slow movements may survive reactivations and thus conserve the evidence of tree topping, tilting or S-shaped stems and scars in their increment series Carrara and O’Neill, ; Stefanini, , spatial and temporal patterns of past landsliding can be dated using tree-ring samples from stem.