Simon Matthias May

University of Cologne | UOC · Institute of Geography

As located in one of the oldest and driest deserts on Earth, soils in the Atacama Desert are greatly affected by atmospheric dust deposited on soil surface and the related fate of water-dispersible colloids (WDCs, <300 nm). We hypothesize that formation and content of these WDCs change with topography and age of natural soils. To highlight the proc...

A complete annual cycle of the dynamics of fine-grained sediment supplied by the Omo and smaller rivers is simulated for Lake Turkana, one of the world’s large lakes, with the hydrodynamic, wave and sediment transport model Delft3D. The model is forced with river liquid and solid discharge and wind data in order to simulate cohesive sediment transp...

Recent research indicates an inverse relation between Synthetic Aperture Radar (SAR) signal and near-surface soil moisture (SM) over very dry sediments, arid to hyper-arid soils resp., caused by subsurface scattering effects. This phenomenon can lead to large errors when it comes to modelling and remote sensing-based estimation of SM. While the eff...

Phoenicians were the first to systematically develop the area surrounding the Strait of Gibraltar at the end of the 9th century B.C. Following pioneering studies in the Río Guadiaro estuary (Málaga/Cádiz) in the 1980s, a German‐Spanish cooperation project focussed on the role of indigenous people in the Phoenician colonisation trading networks at L...

Over the past decades, substantial progress has been made in tsunami research. Be that as it may, little is still known about tsunami deposits and their related depositional mechanisms in coastal areas in historical and archaeological contexts. In particular, the Phoenician, Greek and Roman trade and military networks along the Mediterranean and At...

While shorelines around playa lakes have traditionally played a key role for reconstructing late Quaternary megalakes in drylands, little attention has been given to recent shorelines associated with episodic filling events of modern ephemeral playa lakes such as Kati Thanda-Lake Eyre in central Australia. We here present results from geomorphic ma...

Wave-transported boulders represent important records of storm and tsunami impact over geological timescales. Their use for hazard assessment requires chronological information on their displacement that in many cases cannot be achieved by established dating approaches. To fill this gap, this study investigated, for the first time, the potential of...

In southern Iberia, the surroundings of the Strait of Gibraltar are known as a crossroad for population movements, cultural exchanges, and trade from Late Prehistory to modern times. However, questions remain about the impact of this historical development on the environment. The settlement of La Silla del Papa, an important hillfort in southern An...

Chronostratigraphic investigations on coastal sedimentary records such as washover fans or beach-ridge sequences may be used to reconstruct storm chronologies on centennial to millennial time scales. However, modern analogs are pivotal in interpreting depositional processes and reducing uncertainty in evaluating the complex chronostratigraphic arch...

Increasing population and economic pressures along the world's coastlines have made, and are continuing to make coastal communities more vulnerable to hazards. The hazard management of tsunamis and other extreme waves (storm waves, seiches, infragravity waves) is based on the assessment of the frequency-magnitude relationship of these events, which...

The spatial distribution of boulder deposits along rocky coastlines provides important implications for estimating the hazard of extreme waves (storms or tsunamis). However, rocky coasts are highly dynamic environments, and their changes through time have to be considered when analyzing the coarse-clast record and inferring characteristics of past...

Geological Records of Tsunamis and Other Extreme Waves provides a systematic compendium with concise chapters on the concept and history of paleotsunami research, sediment types and sediment sources, field methods, sedimentary and geomorphological characteristics, as well as dating and modeling approaches. By contrasting tsunami deposits with those...

Wave-transported boulders represent important records of storm and tsunami impact over geological timescales. Their use for hazard assessment requires chronological information that in many cases cannot be achieved by established dating approaches. To fill this gap, this study investigated, for the first time, the potential of optically stimulated...

The hyperarid parts of the Atacama Desert, N Chile, are among the driest places on Earth, and a number of studies have emphasized the remarkable slowness of Earth surface processes since the late Tertiary. Despite episodic overland flow or flash flood activity, salt-driven shrink-swell processes, dust deposition, and seismic shaking have significan...

This study investigates synthetic aperture radar (SAR) time series of the Sentinel-1 mission acquired over the Atacama Desert, Chile, between March 2015 and December 2018. The contribution analyzes temporal and spatial variations of Sentinel-1 interferometric SAR (InSAR) coherence and exemplarily illustrates factors that are responsible for observe...

Colloids and their subset nanoparticles are key soil constituents for nutrient and Organic Carbon (OC) storage and transport, yet little is known about their specific role in overall transfer of elements under hyper-arid conditions. We analyzed the Water Dispersible Colloids (WDCs) of two adjacent soil profiles, located either on the active (named:...

Geological records indicate that the hyper-aridity in the Atacama Desert has prevailed since at least the Mid-Miocene. The 7-metre accumulation of colluvial sediments at the Salar Grande (21°S/70°W) studied here provides a fundamental palaeoclimate record to understand hillslope dynamics and its relation to humid periods. While 10Be surface exposur...

Hillslopes represent areas of predominant denudation and constitute the transition and trajectory to floodplains; they play a crucial role in understanding the long-term landscape evolution of desert environments. However, although hillslope processes are known to be very slow or even stagnant in (hyper-) arid environments, process mechanisms under...

Hillslopes represent areas of predominant denudation and constitute the transition and trajectory to floodplains; they play a crucial role in understanding the long-term landscape evolution of desert environments. However, although hillslope processes are known to be very slow or even stagnant in (hyper-)arid environments, process mechanisms under...

Although a number of studies have pointed out the remarkable slowness of Earth surface processes in the Atacama Desert, process mechanisms under such extremely limited water availability are poorly understood, and process rates remain unknown. This paper revisits the discussion on the formation of the prominent Atacama-specific hillslope zebra (sto...

In the southernmost part of the Colchian plain (Georgia), the Supsa and Rioni rivers represent important catchments for reconstructing Holocene landscape changes. Using granulometric methods, geochemical analyses and radiocarbon dating, we demonstrate that significant palaeoenvironmental changes have taken place in the surroundings of the Supsa fan...

Establishing patterns of frequency and magnitude of erosion events is key for understanding landscape evolution. For that purpose, luminescence dating is one of the most useful techniques as it can provide accurate chronology for sediment deposition. In this study, it has been applied to two stratigraphic profiles at the slopes of the Salar Grande,...

The hyperarid parts of the Atacama Desert, N Chile, are among the driest places on Earth, and a number of studies have emphasized the remarkable slowness of earth surface processes since the late Tertiary. Nevertheless, geomor-phic processes such as overland flow or flash flood activity, salt-driven shrink-swell processes, dust deposition, or seism...

Quartz is the preferred dosimeter for luminescence dating of Holocene sediments as optically stimulated luminescence (OSL) signals reset rapidly upon light exposure, and are stable over time. However, feldspar is required where quartz luminescence properties are inappropriate for dating, as is often the case in geologically young mountain ranges an...

The cover image, by Hannes Laermanns et al., is based on the Research Article Bronze Age settlement mounds on the Colchian plain at the Black Sea coast of Georgia: A geoarchaeological perspective, DOI: 10.1002/gea.21670.

Past coastal flooding events may be inferred from geomorphic and sedimentary archives, including particular landforms (e.g., beach ridges, washover fans), deposits (e.g., washover sediments in lagoons) or erosional features (e.g., erosional scarps within strandplains). In Giralia Bay, southern Exmouth Gulf (Western Australia), sandy ridge sequences...

Dating the transport/deposition time of supratidal coarse-clast deposits is difficult, limiting their value for inferring frequency-magnitude patterns of high-energy wave events. On Bonaire (Leeward Antilles, Caribbean), these deposits form prominent landforms, and transport by one or several Holocene tsunamis is assumed at least for the largest cl...

Marine conglomerates at high elevation on the flanks of ocean islands are usually interpreted as evidence of mega-tsunamis generated by volcano flank collapses, although their origin is sometimes debated (elevated littorals vs. tsunami). In this review, we introduce case studies of well-documented examples of tsunami conglomerates in Hawaii (Pacifi...

While rates of hillslope processes and soil formation are known to be typically very low or stagnant under the hyper-arid conditions of the Atacama Desert, information on process rates and the influence of protective gypsum crusts on hillslope morphodynamics is scarce. Within the framework of the DFG-funded CRC 1211 "Earth-Evolution at the dry limi...

The DFG-funded Collaborative Research Centre 1211 (CRC 1211) "Earth-Evolution at the dry limit" pioneers the research on the mutual evolutionary relationships between earth surface processes and biota in arid and hyper-arid areas of the Earth. In the Atacama Desert, a number of studies have pointed out the remarkable slowness of earth surface proce...

Situated between the Enguri and Khobistskali rivers, more than 30 settlement mounds (locally named Dikhagudzuba) provide evidence for a relatively densely populated landscape in the coastal lowlands of western Georgia during the Bronze Age. Compared to older mounds in eastern Georgia and other regions, these mounds differ not only in age but also i...

Washover fans typically form due to barrier overwash or breaching and coastal inundation and generally represent geomorphological and depositional evidence of intense storms. Few studies have investigated the chronostratigraphy of washover fans in order to infer magnitude/frequency patterns of extreme-wave events over longer time scales. Here we pr...

Fields of wave-emplaced blocks and boulders represent impressive evidence of cyclone and tsunami flooding over Holocene time scales. Unfortunately, their use for coastal hazard assessment is in many cases impeded by the absence of appropriate dating approaches, which are needed to generate robust chronologies. The commonly applied AMS-14C, U/Th or...

The Kolkheti lowlands (Colchis, Colchian plain) form the central part of the extensive coastal lowlands along the Black Sea coast of Georgia. Situated between the Greater and the Lesser Caucasus, favourable climatic conditions resulted in a constant human occupation of the region during the Holocene. However, due to continued deltaic sedimentation...

Reliable age dating of coastal sedimentary landforms is crucial for inferring storm frequencies and magnitudes from geological archives. However, in highly energetic coastal settings, radiocarbon dating is often biased by reworking and/or poorly constrained marine reservoir effects. Due to this, most cyclone-driven sediment archives from the semiar...

On November 8 th 2013, category 5 Supertyphoon Haiyan made landfall on the Philippines. During a post-typhoon survey in February 2014 Haiyan-related sand deposition and morphological changes were documented at four severely affected sites with different exposure to the typhoon track, and different geological and geomorphological settings. Extended...

On 8 November 2013, category 5 Supertyphoon Haiyan made landfall on the Philippines. During a post-typhoon survey in February 2014, Haiyan-related sand deposition and morphological changes were documented at four severely affected sites with different exposure to the typhoon track and different geological and geomorphological settings. Onshore sand...

Coastal areas are vulnerable to the impacts of tropical cyclones (TC), tsunamis and other water super‐elevation events, but the frequency of these events is often poorly represented by conventional records. Coastal overwash deposits (including washover fans) can provide a longer‐term archive of event frequency. Because of their low‐gradient geomorp...

Coasts worldwide experience considerable population pressure and the demand for reliable hazard management, such as of tsunamis, increases. Tsunami hazard assessment requires information on long-term patterns of frequency and magnitude, which are best explained by inverse power-law functions. In areas with a short historical documentation, long-ter...

Although frequently occurring, little is known about the geological imprint of (pre)historical tropical cyclones (TCs) in Northwestern Australia. Large washover fans at Point Lefroy (Exmouth Gulf) provide unambiguous mor- phological evidence of flooding by TCs capable to overtop and breach the local coastal barrier. Based on ground penetrating rada...

Coastal zones worldwide experience considerable population pressure and demand for a management of hazards such as tsunamis. Tsunami hazard assessment is the initial step of the management process and requires reliable information on frequency and magnitude. In areas with short historical documentation, these long-term frequency-magnitude patterns,...

Boulder fields record maximum magnitudes of coastal flooding during strong storms or tsunamis. Such a maximum magnitude tropical cyclone – Supertyphoon Haiyan – made landfall in the Philippines on 8 November 2013. During this typhoon, longshore transport of blocks of up to 180 t and upslope transport of boulders weighing up to 23.5 t to elevations...

Although extreme-wave events are frequent along the northwestern coast of Western Australia and tsunamis in 1994 and 2006 induced considerable coastal flooding locally, robust stratigraphical evidence of prehistoric tropical cyclones and tsunamis from this area is lacking. Based on the analyses of X-ray computed microtomography (μCT) of oriented se...

Fields of dislodged boulders and blocks record catastrophic coastal flooding during strong storms or tsunamis and play a pivotal role in coastal hazard assessment. Along the rocky carbonate coast of Eastern Samar (Philippines) we documented longshore transport of a block of 180 t and boulders (up to 23.5 t) shifted upslope to elevations of up to 10...

Fields of dislocated boulders and blocks record catastrophic coastal flooding during strong storms or tsunamis and play a pivotal role in coastal hazard assessment. Along the rocky carbonate coast of Eastern Samar (Philippines) we documented longshore transport of a block of 180 t and boulders (up to 23.5 t) shifted uphill to elevations of up 5 to...

Working with a large temporal dataset spanning several decades often represents a challenging task, especially when the record is heterogeneous and incomplete. The use of statistical laws could potentially overcome these problems. Here we apply Benford's Law (also called the "First-Digit Law") to the traveled distances of tropical cyclones since 18...

The Holocene evolution of the Canning Coast of Western Australia has largely been overlooked so far mainly due to its remoteness and low population density. We report on new data from a sequence of foredunes inside the macrotidal Admiral Bay, 110 km southwest of Broome. Based on sediment cores, DGPS-based elevation transects, and stratigraphical an...

At coasts around the world where the impact of storm waves or tsunamis is known or assumed, large boulders and marine sands at coastlines are used as indicators for particular event characteristics and occurrence patterns over large time scales. Such deposits identified at the coast of Bonaire (Leeward Antilles) point to a tsunami hazard, which is...

“A heavyweight for Einstein – Probing gravity where no one has done it before”. This was the headline of a press release in April 2013 by the Max Planck Institute for Radio Astronomy (Bonn, Germany). John Antoniadis, a student of the institution and his colleagues put Einstein’s general theory of relativity to the test in a cosmic laboratory 7,000...

Since the beginning of the times of industrialization man has transformed large parts of the global surface by technical installations such as dams, quarries, and open pit mining. However, a direct geomorphologic transformation of the slopes has also taken place since thousands of years and in very large areas for the cultivation of crop (and wet r...

Planar forms as individual geomorpic forms may be very extensive, but are rather rare on Earth, because they usually require long geologic time spans to form (millions or tens of millions of years). Nevertheless, there are typical planar forms according to climate provinces like the glacis or pediments in arid and semi-arid environments along the f...

Our early ancestors were just spreading out of Africa and east across Asia when one of the most explosive volcanic eruptions on Earth in the last two million years took place at 73,880 years ago (with a margin of error of just a few centuries) in northern Sumatra. The scientific team who dated the event works on the hypothesis that the Toba eruptio...

Water is the most precious element on our planet, and therefore rivers also are called “veins of life”, particularly in arid or semi-arid landscapes. Rivers, however, are the forces which form valleys by cutting linear to oscillating depressions into the landscape. Even if the river is no longer present, we can easily identify the valleys as the re...

Glacier ice forms from accumulated old snow, and the erosive power of glaciers flowing down-valley as well as the related production and deposition of large amounts of rock debris are responsible for the large inventory of glacial landforms. Even though we are living in a warm climatic period at the moment (the Holocene interglacial period), glacie...

In 1980, father and son geologists Luis and Walter Alvarez discovered unusually high traces of iridium in rock layers near Gubbio (Italy) that define the Cretaceous-Paleogene boundary (K-Pg; formerly known as the K-T boundary) when about 75 % of all species on Earth, including the dinosaurs, perished forever in a mass extinction event. The Alvarez’...

Water is essential to a wide variety of geological processes, both as a solvent of minerals in rock and soil and as a transport agent that carries away dissolved and weathered materials. The development of all karst landforms requires the presence of rock types capable of being dissolved by surface water or ground water. Throughout the world, karst...

Frost is not only an important agent to destroy rocks by frost shattering, but as permanent frost (permafrost) in the ground (either in sediment, soil or even hard rock) it also contributes to distinctive patterns in the landscape (called “patterned ground”). Some are only centimeters wide, while others can be seen for many square kilometers. The e...

Landscapes are shaped by the uplift, deformation and breakdown of bedrock and the erosion, transport and deposition of sediment in a constant cycle of change that operate since the early stages of the formation of our home planet over four billion years ago. The forces of nature that drive these changes originate from processes operating within the...

As one geologist exclaimed: “Savor the irony should the metamorphic muscles that push mountains to the sky be driven by the pitter patter of tiny raindrops.” In the following chapters we look at this pitter patter, a synonym for exogenic processes that shape our landforms, starting with the most important process: weathering. Weathering takes place...

Compared with the erosive force of moving glaciers and flowing rivers, wind seems to be a less effective agent when it comes to the evolution of landscapes and the generation of landforms. While this idea may be true for the destructive aeolian process of deflation and its resulting landforms, the depositional aeolian processes such as dune formati...

If you come across igneous rocks consisting of coarse-grained minerals in a landscape, chances are you are standing on an igneous intrusion that crystallized several kilometers below the Earth’s surface. Igneous intrusions are fascinating windows into magmatic processes that take place deep in the Earth’s crust and cannot be observed directly with...

Why is the Earth so restless and relentlessly changing? And what forces can tilt, bend or fracture rocks that seem so rigid and strong into wild and amazing patterns of folds, faults or fractures? Early geologists who understood all too well that most sedimentary rocks had been laid down as soft, horizontal layers have wrestled with questions such...

Although the north-western coast of Western Australia is highly vulnerable to tropical cyclones and tsunamis, little is known about the geological imprint of historic and prehistoric extreme wave events in this particular area. Despite a number of site-specific difficulties such as post-depositional changes and the preservation potential of event d...

This book describes all types of terrestrial environments and landforms at a glance, through over 250 full-colour images from Google Earth including scales, coordinates, explanatory text and references. It contains more images than text and is easy to comprehend for everyone interested in landform processes active on our globe.It enriches the under...

The coastal deposits of Bonaire, Leeward Antilles, are among the most studied archives for extreme-wave events (EWEs) in the Caribbean. Here we present more than 400 electron spin resonance (ESR) and radiocarbon data on coarse-clast deposits from Bonaire’s eastern and western coasts. The chronological data are compared to the occurrence and age of...

http://www.geographischerundschau.de/heft/51140600/Ausgabe-Juni-Heft-6-2014-Digitale-Geographie#rubrik2

Along the Chilean–Peruvian coast, numerous archaeological sites associated with shell accumulations provide evidence for the role of coastal environments as a natural corridor for the human occupation of South America. In particular, the semi-arid coastline of northern Central Chile (∼33–27° S) is a key area for investigating the relationship betwe...

Throughout the whole river network of the Rhenish Massif, the terrace complex of the so-called Main Terrace forms the morphological transition between a wide upper palaeovalley (plateau valley) and a deeply incised lower valley. The youngest level of this Main Terrace complex (YMT), directly located at the edge of the incised valley, represents a d...

Future relative sea-level (RSL) rise is one of the most serious coastal hazards worldwide, in particular in the Caribbean region. RSL is a function of global (glacioeustasy, steric effect), regional (e.g. glacioisostatic adjustment [GIA], gravitational effects inducing deformation of the Earth, upper/lower mantle viscosity, etc.) and local (lithoso...

Aware of past and future climate changes, the question arose whether modern instrumental data adequately reflect the chronology of tropical cyclones and extratropical winter storms for the period of the present eustatic sea level highstand (approx. the past 6,000 years). For pre-instrumental times, geological and sedimentological methods have been...