In recent decades, international assessments of the ocean have evolved from specialized, technical evaluations of the state of the marine environment to more integrated and thematically extensive science-policy platforms. As assessment programmes such as the UN Regular Process blossom on the global stage and subsume responsibility for tracking progress on sustainable development, there is a need to consider how their processes wield influence and effectively translate knowledge into action. In the present paper, we undertake a comprehensive review of the literature on global environmental assessments (GEAs) and extract key principles that can be applied to global assessments of the marine environment. We were particularly inspired to identify how social processes could be arranged to best distill, communicate, and produce actionable knowledge. While we look to the advice of experts in the literature, we highlight specific examples from the Intergovernmental Panel on Climate Change (IPCC), Intergovernmental Science-Policy Platform on Biodiversity and Ecosystem Services (IPBES), and the Global Environment Outlook (GEO). From this review, knowledge coproduction, multilevel collaboration, and futures thinking emerged as the dominant principles of influential and action-oriented assessments. We conclude the paper by contextualizing how these principles may be operationalized for Global Marine Assessments in the future.

Risks posed by sea-level rise and cyclones are becoming more prevalent along the world’s coastlines. In recent years, tsunamis have had devastating impacts on communities in different ocean basins. Although storms and tsunamis can be clearly distinguished when they occur in the present, this does not apply to the past, from which only their traces in the form of sedimentary or geomorphologic features provide clues about their occurrence. Following a short review of research on tsunamis from the last decades, this study uses the example of coastal boulder deposits to highlight where knowledge gaps exist. This report focuses on the spatial distribution of sediment patterns and how these may provide clues to the transport processes. However, the history of these deposits and related sea-level records during the same time span must also be recorded and contextualized. Theoretical modeling results without including these parameters will remain fuzzy, if not inaccurate. This contribution points to the need for consideration of both data and nature’s reality (which are complementary and interdependent) in this field.

Research into boulder deposits by tsunamis and strong storms is still in its infancy. Tsunami provenience often is rejected for older deposits because boulders are not typical or important objects dislocated by tsunami events. However, this assumption is not supported by the physics of tsunami inundation flow. This paper focuses on the wide variety of environmental factors and field data that support boulder transport and deposition due to historical tsunami events. It considers the character of single boulders and boulder accumulations, as well as how dislocation age and sea-level history are interlinked. For historical events, methods to reconstruct environmental conditions such as shoreline character, boulder form and size during transport, preservation status, changes in sea level and, in particular, age of the dislocation event, and later impact processes are also important. Without such data, numerical modeling of erosional and depositional processes due to tsunamis is not conclusive.

There are a myriad of laws, guidelines and unwritten agreements relating to human, hominid and hominin remains. Legal gaps and inadequate definitions of what constitutes a fossil have meant that a ‘finders keepers’ approach is often applied to the ownership and control of our ancestors' remains. Such shortcomings expose numerous legal and ethical conundrums. Should any one organisation, individual or government control access to recently-found remains, limiting opportunities to unlock the secrets of evolution? Given that humans can start fossilisation processes immediately after burial, at what point does it become appropriate to dig up their remains? And who should control access to them? Could any prehistoric Homo ever have imagined they would one day be exhumed and their remains laid out in cases as the centrepiece of a museum exhibit? This paper surveys a number of implications that arise from these foundational questions, and ultimately challenges the belief that human, hominin and hominid remains are self-evident ‘objects’ capable of clear ownership: rather they constitute creative cultural intersections, which are deserving of greater ethical consideration. Protocols for respecting, protecting and conserving remains while allowing a greater equity in access to information about our common ancestors are both desirable and urgently required.

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 events. This chapter reviews the impact of extreme waves on the erosion of rocky coasts and the formation of coarse-clast deposits, evaluates the potential of weathering and erosion features for relative dating of coastal erosion and boulder transport, and investigates the relevance of boulder "shrinking" through post-depositional erosion processes.

A longstanding geomorphological debate exists on the capability of high-intensity hurricanes to transport megaboulders. This article considers this debate, with a focus on the Bahamas during the Eemian period when sea levels have been higher. The superstorm hypothesis implies that during a warmer interglacial period, storms of unprecedented intensity would have the ability to dislodge megaboulders, against gravity, and then transport them inland to their current place of deposition, and modelling resulted in strong storms during higher sea levels as the most probable process. In this study, geomorphological arguments are tested that consider the reconstruction of the Eemian coastal landscape, focussing on original dimensions of the boulders and the position of the Eemian cliff more accurately, not excluding tsunamis as a driving force.

The world’s sustainability opportunities and national security challenges converge in the coastal zone. Hundreds of millions of people face increasing pressure from population growth, over exploitation of natural resources, and escalating disaster-risk, as the climate changes and sea levels rise. Global Environmental Assessments have been a tool for international policy makers, and a particular favorite of UN bodies and can add value to national efforts. The first World Ocean Assessment concluded that without an integrated, coordinated, proactive, cross-sectoral and science-based approach to coastal and marine management, the resilience of coastal and marine ecosystems, and their ability to provide vital services, will continue to be reduced. The second World Ocean Assessment is currently under development and will build on the baselines established in the first assessment, by identifying key trends and relevance to the SDGs. However, global assessment processes, may be curtailed by bureaucracy and diplomatic legitimacy, whilst struggling to engage relevant stakeholders and institutions. As a result, there is a need to complement these important top-down, global environmental assessments, with more agile assessment processes, as well as facilitating bottom-up capacity building with stakeholders involved in coastal zone management. This requirement is articulated in the text of the “Our Coastal Futures Strategy”, launched in 2018 by Future Earth Coasts (FEC). We, the FEC program, observe that the assessment process is often not as inclusive as it could be, for example, by separating sectors, such as science and technology, policy, and public engagement throughout the assessment, with inter-sector connections usually made at a later stage in the process. Therefore, we stress the importance of co-designed synthesis that can reach into new knowledge, including tacit knowledge of diverse stakeholders, from the outset. Our Rapid Ocean Assessment Methodology Workshop will address this important issue and achieve a better understanding of the complexities and non-linearities of coastal-zone processes and interactions; fundamental to informing meaningful assessments and identifying potential sustainability pathways.

This article is a response to the publication by Nick Marriner, David Kaniewski, Christophe Morhange, Clement Flaux, Matthieu Giaime, Matteo Vacchi and James Goff entitled "Tsunamis in the geological record: Making waves with a cautionary tale from the Mediterranean", published in October 2017 in Science Advances. Making use of radiometric data sets published in the context of selected palaeotsunami studies by independent research groups from different countries, MARRINER et al. (2017) carried out statistical and time series analyses. They compared their results with an assessment of Mediterranean storminess since the mid-Holocene that was previously published by KANIEWSKI et al. (2016) based on a single-core study from coastal Croatia. MARRINER et al. (2017) now present "previously unrecognized" 1500-year "tsunami megacycles" which they suggest correlating with Mediterranean climate deterioration. They conclude that up to 90 % of all the 'tsunamis' identified in original tsunami papers used for their study are "better ascribed to periods of heightened storminess". In this response, we show that (i) the comparison of statistical data describing storm and tsunami events presented by MARRINER et al. (2017) is incorrect both from a geographical and a statistical point of view, (ii) the assumed periods of central Mediterranean storminess published by KANIEWSKI et al. (2016) are missing convincing geological and geochronological evidence and are statistically incorrect, (iii) the palaeotsunami data that was originally collected by different groups of authors were manipulated by MARRINER et al. (2017) in a way that the resulting data set - used as a benchmark for the entire study of these authors - is wrong and inaccurate, and that (iv) MARRINER et al. (2017) did not address or even negate the original sedimentological studies' presentation of comparative tsunami versus storm deposits for the selected individual localities. Based on a thorough and detailed evaluation of the geoscientific background and the methodological approach of the studies by KANIEWSKI et al. (2016) and MARRINER et al. (2017), we conclude that there is no serious and reliable geoscientific evidence for increased storminess in the (central) Mediterranean Sea between 3400-2550, 2000-1800, 1650-1450, 1300-900 and 400-100 cal BP. The impact of those storms in the Mediterranean, producing geological traces somewhat comparable to those caused by tsunamis, is insignificantly small. For the period 1902-2017, Mediterranean tsunamis make up 73-98 % of all combined extreme wave events (EWE) leading to coastal flooding and appeared up to 181 times deadlier than comparable storm effects. This is the reason why coastal Mediterranean research has focused on Holocene records of the tsunami hazard, while research on comparable storm effects is of lower significance. The validity of geological evidence for Mediterranean EWE and their interpretation as caused by palaeotsunami impacts thus remains untouched. Tsunamis, in most cases directly and indirectly induced by seismo-tectonics, have always been a much greater threat to Mediterranean coastal regions than comparable storm effects. 'Tsunami megacycles' as expressions of a 1500-year periodicity centered on the Little Ice Age, 1600 and 3100 cal BP that were correlated with questionable storm data do not exist. Cause and effect relationships work the other way round: Major tsunami events, testified by historical accounts, such as those that occurred in 1908 AD, 1755 AD, 1693 AD and 365 AD, induced numerous studies along Mediterranean coasts. These investigations resulted in a large number of publications that specifically focus on those time periods, suspected by MARRINER et al. (2017) to bear signs of increased storminess, namely 200-300 BP and 1600 BP. The Mediterranean tsunami record cannot be ascribed to periods of increased storminess. On the contrary, the tsunami record as interpreted by the authors of the original papers cited by MARRINER et al. (2017), is due to the outstandingly high seismo-tectonic activity of the region. Mediterranean tsunamis are mostly triggered by earthquakes or by earthquake-related secondary effects such as underwater mass movements. The study by MARRINER et al. (2017) is also problematic because it includes simple basic statistical mistakes and major methodological inconsistencies. The geomorphological and sedimentary background of EWE deposits was not taken into account. The 'broad brush' approach used by MARRINER et al. (2017) to sweep sedimentary deposits from tsunami origin into the storm bag origin, just on the basis of (false) statistics coupled with very broad and unreliable palaeoclimatic indicators and time frames, is misleading. The distortion of original data collected and interpreted by other research groups by MARRINER et al. (2017) is particularly disturbing. Their publication is also bound to question in this case the effectiveness of scientific quality assurance in modern publishing commerce. MARRINER et al. (2017: 77) talk down the considerable risk to human settlements and infrastructure along Mediterranean coasts in relation to tsunami and earthquake hazards. Their conclusion is not only wrong as a result of their incorrect data mining and analyses, it is also irresponsible with regard to national and international efforts of tsunami and earthquake risk mitigation.

This study is concerned with large boulders located along exposed shorelines in higher latitudes, which have become dislocated onshore by winter storms and have moved against gravity. To identify the transportation processes that these boulders have undergone in detail, their direct investigation during storm wave conditions is necessary, or at least near time inspections after extraordinary wave events. As both methods are rare, a wide range of questions and contradictions with regards to the processes that have acted on these boulders, remains. Despite a lack of applicable methods as for fine sediments, the depositional environment and processes of boulder movement can be determined from geomorphologic evidence in the landscape itself. Examples are presented in this paper. To progress understanding of boulders in rocky coastal environments, qualitative and quantitative data are acquired during a near time inspection following extreme storms in winter 2013/14 with special focus on an extraordinary boulder site near Doolin at the entrance to Galway Bay (central west coast of Ireland). The comparison of these data to previously published research on coastal boulder movement results in agreements and discrepancies (e.g. on boulder forms and mode of transport, difference in wave and bore transport) which are discussed.

Rocky shores predominantly comprising coarse gravel and boulders are a neglected area of research, in part because of the difficulty in undertaking laboratory analyses on such environments. This paper is concerned with the geomorphology of the deposition of exceptional large boulders in cliff-top positions along the Aran Islands' Inishmaan, Inishmore, and Inisheer coast. These deposits are compared with other depositional units such as isolated finer sediment archives and tonguelike washover features associated with small to medium-sized boulders. Micromorphological signatures from limestone dissolution onshore and bioerosive patterns from the tidal frame were also investigated, with particular consideration of the relative age of boulder movement. Field studies included near-time inspection of the transport power during the strongest storms in living memory in winter 2013-14. To explore spatial and temporal variation in boulder deposition, numerical data for event chronologies are included. The paper also discusses rates of cliff retreat and movement of boulder ridges and contains an evaluation of the storm-only hypothesis vs. contribution of tsunamis to boulder movement.

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 in supratidal elevations form the landward margin of extensive mudflats. The formation of these ridges is assumed to be mainly driven by tropical cyclones (TCs), although their depositional processes need to be clarified. We investigated the supratidal sandy ridge sequence in Giralia Bay by carrying out process monitoring, geomorphological mapping by means of an unmanned aerial vehicle survey, as well as sedimentological and geochronological investigations and multivariate statistics. Based on the resulting data, this study aims at (i) identifying the most important driving processes to form the sandy ridges; (ii) establishing their chronostratigraphy; and (iii) understanding their significance for recording past TC activity. Trench excavations revealed sandy units that are interbedded with mud layers at the base, similar to the present distal mudflat sediments. On top, mud intercalations recede, and sand layers of varying grain size distribution dominate. In the upper part of the trenches, younger sediment layers onlap older ones documenting the stepwise seaward accretion of the ridges onto the mudflat. While our data suggests that tidal processes have only limited effects on ridge activity, sediment transport, erosion and deposition seems to be driven by both TC-induced storm surges and high magnitude precipitation events causing surface discharge. Most accretionary sand units are thus assumed to represent events of morphodynamic activity during TC-induced flooding since the mid-Holocene. Ridge activity is recorded in a roughly decadal resolution and over historical as well as prehistorical/Holocene time scales. While the ridges do not represent beach or chenier ridges sensu stricto, they may be described as chenier-type ridges due to their stratigraphical architecture. Ridge evolution, however, over a millennial time scale seems to be indicated by the landward rise of the sequence possibly corresponding to the mid-Holocene sea-level highstand of Western Australia of at least 1–2m above present mean sea level.

This paper aims to study and compare the obsidian economies of Renaghju and I Stantari, two neighbouring Neolithic sites located on the Cauria plateau (south-western Corsica). The occupation phase 3 of Renaghju and phase 1 of I Stantari, both attributed to the Middle Neolithic (fifth millennium BC), have provided respectively 112 and 99 obsidian artefacts. With the aim of completing our rather lacunary knowledge of the obsidian consumption behaviours in place in Corsica during this period, the entire assemblages have been geochemically characterised virtually non-destructively using LA-ICP-MS at SOLARIS (Southern Cross University [SCU]). Our analyses revealed that, while the obsidian raw materials were exclusively sourced from the Monte Arci complex in Sardinia (SA, SB2, and SC sub-types only), rather different consumption patterns are observed for the two sites despite their comparable nature (megalithic sites) and geographical proximity (400 m apart). These differences in obsidian consumption on adjacent sites could be explained by their divergent functions (ceremonial site [Renaghju] vs. ceremonial locus and large settlement [I Stantari]), or eventually point towards the need for a readjustment of the chronological attribution of the I Stantari phase 1 occupation level. (C) 2017 Elsevier Ltd and INQUA. All rights reserved.

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 present new data on the chronostratigraphy of late Holocene washover fans in the Exmouth Gulf (Western Australia) by using ground penetrating radar and unmanned aerial vehicle (UAV) survey techniques, as well as geomorphological, sedimentological and chronological investigations. This study aims to (i) provide a detailed characterization of the washover fans' geomorphology and stratigraphical architecture; (ii) document depositional processes involved in their formation; (iii) establish a chronostratigraphy based on optically stimulated luminescence (OSL); and (iv) understand the significance of the washover fans for recording past tropical cyclone (TC) activity. The fans consist of multiple sequences of sand, shell debris and coral rubble comprising depositional units related to TC-induced inundation. The units are separated by palaeosurfaces with incipient soil formation, formed during periods of reduced depositional activity. In combination with the interpretation of a UAV-based high-resolution digital surface model, multiple phases of reactivation are inferred. OSL results allow the establishment of a local long-term TC record and suggest storm-induced deposition at ∼170, ∼360, ∼850 and ∼1300 years ago. Further units were dated to ∼1950, ∼2300, and ∼2850 years ago. The chronology of TC events is consistent with other work relating TC activity with El Niño Southern Oscillation (ENSO) and sea surface temperature (SST) patterns, corroborating the regional palaeotempestological relevance of this unique geomorphological record.