Daniel Melnick

Universidad Austral de Chile · Instituto de Ciencias de la Tierra

Charles Darwin and Robert FitzRoy documented coseismic coastal uplift associated with the great 1835 Chile earthquake (M>8.5) at Isla Santa María. In 2010, another similar earthquake (Mw 8.8) uplifted the island, ending the seismic cycle. The 2-m uplift in 2010 caused major geomorphic and sedimentologic changes to the island’s sandy beaches. Unders...

We deployed a dense geodetic and seismological network in the Atacama seismic gap in Chile. We derive a microseismicity catalog of >30,000 events, time series from 70 GNSS stations, and apply a transdimensional Bayesian inversion to estimate interplate locking degree. We identify two highly locked regions of different sizes whose geometries appear...

The first step towards assessing hazards in seismically active regions involves mapping capable faults and estimating their recurrence times. While the mapping of active faults is commonly based on distinct geologic and geomorphic features evident at the surface, mapping blind seismogenic faults is complicated by the absence of on-fault diagnostic...

The first step towards assessing hazards in seismically active regions involves mapping capable faults and estimating their recurrence times. While the mapping of active faults is commonly based on distinct geologic and geomorphic features evident at the surface, mapping blind seismogenic faults is complicated by the absence of on-fault diagnostic...

Magmatic continental rifts often constitute nascent plate boundaries, yet long‐term extension rates and transient rate changes associated with these early stages of continental breakup remain difficult to determine. Here, we derive a time‐averaged minimum extension rate for the inner graben of the Northern Kenya Rift (NKR) of the East African Rift...

The tsunami associated with the giant 9.5 Mw 1960 Chile earthquake deposited an extensive sand layer above organic‐rich soils near Queule (39.3°S, 73.2°W), south‐central Chile. Using the 1960 tsunami deposits, together with eye‐witness observations and numerical simulations of tsunami inundation, we tested the tsunami inundation sensitivity of the...

The Gofa Province and the Chew Bahir Basin of southern Ethiopia constitute tectonically active regions, where the Southern Main Ethiopian Rift converges with the Northern Kenya Rift through a wide zone of extensional deformation with several north to northeast-trending, left-stepping en-échelon basins. This sector of the Southern Main Ethiopian Rif...

Subduction zone earthquakes result in some of the most devastating natural hazards on Earth. Knowledge of where great (moment magnitude M ≥ 8) subduction zone earthquakes can occur and how they rupture is critical to constraining future seismic and tsunami hazards. Since the occurrence of well-instrumented great earthquakes, such as the 2004 M9.1 S...

Assessing tsunami hazards commonly relies on historical accounts of past inundations, but such chronicles may be biased by temporal gaps due to historical circumstances. As a possible example, the lack of reports of tsunami inundation from the 1737 south-central Chile earthquake has been attributed to either civil unrest or a small tsunami due to d...

Time-dependent earthquake forecast depends on the frequency and number of past events and time since the last event. Unfortunately, only a few past events are historically documented along subduction zones where forecasting relies mostly on paleoseismic catalogs. We address the role of dating uncertainty and completeness of paleoseismic catalogs on...

Tectonically active coasts are dynamic environments characterized by the presence of multiple marine terraces formed by the combined effects of wave erosion, tectonic uplift, and sea-level oscillations at glacial-cycle timescales. Well-preserved erosional terraces from the last interglacial sea-level highstand are ideal marker horizons for reconstr...

We present a formal seismic segmentation model of the Chile Margin derived from a multivariate analysis of gravity anomalies, basal friction and interplate locking from GPS velocities. These independent proxies of the frictional structure along the megathrust integrate over timescales of 101 to 107 years. We analyze their covariance using Principal...

Corals reveal that part of the plate-boundary fault near Sumatra slipped slowly and quietly for three decades before a large earthquake in 1868. The exceptional duration of this slip event has implications for interpreting deformation to assess seismic hazard.

We present evidence of land‐level change resulting from the 2016 Mw 7.6 Chiloé earthquake from tidal wetlands along the southern coastline of Isla de Chiloé, Chile, to test criteria for the detection of low‐level, <0.1 m, coseismic land‐level change. In order to record coseismic land‐level change in tidal wetland sediments, both the creation and pr...

In active tectonic settings dominated by strike-slip kinematics, slip partitioning across subparallel faults is a common feature; therefore, assessing the degree of partitioning and strain localization is paramount for seismic hazard assessments. Here, we estimate a slip rate of 18.8 ± 2.0 mm/year over the past 9.0 ± 0.1 ka for a single strand of t...

Evaluating the transfer of stresses from megathrust earthquakes to adjacent segments is fundamental to assess seismic hazard. Here, we use a 3D forward model as well as GPS and seismic data to investigate the transient deformation and Coulomb Failure Stresses (CFS) changes induced by the 2010 Maule earthquake in its northern segment, where the Mw 8...

At Chaihuín marsh, south of Valdivia (39°56’ S/73°33’ W), a sand bed was deposited during the 1960 earthquake. The aim of this study is to map the 1960 tsunami deposit in detail and to associate earlier sand layers with past tsunamis. Geologic field mapping by means of stratigraphic sections constructed using 111 cores in the marsh revealed the exi...

In seismically-active regions, mapping active and potentially-active faults is the first step to assess seismic hazards and site selection for paleoseismic studies that will estimate recurrence rates. Here, we present a comprehensive database of active and potentially-active continental faults in Chile based on existing studies and new mapping at 1...

Fuentes sísmicas y tsunamigénicas en Chile

Tectonically active coasts are dynamic environments characterized by the presence of multiple marine terraces formed by the combined effects of wave-erosion, tectonic uplift, and sea-level oscillations at glacial-cycle timescales. Well-preserved erosional terraces from the last interglacial sea-level highstand are ideal marker horizons for reconstr...

The 2018 Palu tsunami contributed significantly to the devastation caused by the associated Mw 7.5 earthquake. The tsunami event led to a debate about how the moderate size earthquake triggered such a large tsunami within Palu Bay, with runups of more than 10 m. The possibility of a large component of vertical coseismic deformation and submarine la...

The southern margin of the Central Anatolian Plateau (CAP) records a strong uplift phase after the early Middle Pleistocene, which has been related to the slab break‐off of the subducting Arabian plate beneath the Anatolian microplate. During the last 450 kyr the area underwent an uplift phase at a mean rate of ~3.2 m/kyr, as suggested by Middle Pl...

In seismically-active regions, mapping capable faults and estimating their recurrence time is the first step to assess seismic hazards. Fault maps are commonly based on geologic and geomorphic features evident at the surface; however, mapping blind faults and estimating their seismic potential is challenging because on-fault diagnostic features are...

High-resolution records of lake-level changes are crucial to elucidate the impact of local and global climatic changes in lacustrine basins. The Late Quaternary evolution of the Dead Sea has been characterized by substantial variability apparently linked with global climatic changes, beign subject of many research e orts since decades. Previous stu...

We present a comprehensive relative sea-level (RSL) database for north, central, and south-central Chile (18.5°S – 43.6°S) using a consistent, systematic, and internationally comparable approach. Despite its latitudinal extent, this coastline has received little rigorous or systematic attention and details of its RSL history remain largely unexplor...

The morphology of marine and lacustrine terraces has been largely used to measure past sea-and lake-level positions and estimate vertical deformation in a wealth of studies focused on climate and tectonic processes. To obtain accurate morphometric assessments of terrace morphology we present TerraceM-2, an improved version of our Matlab R graphic-u...

In the Southern Andes between 38°S and 48°S, the Liquiñe-Ofqui Fault Zone (LOFZ) occurs as a dextral transpressive intra-arc fault zone that partially absorbs the margin parallel component of oblique convergence between the Nazca and South American plates (Lavenu & Cembrano, 1999). Slip rates along this structure have been estimated only at the mil...

Loading and unloading of the crust controlled by lake level changes may exert a important influence on the patterns of surface deformation, seismogenesis and fault activity. However, the relative contribution of climatic and tectonic factors on surface deformation at millennial time scales still remains poorly understood and quantified. The Dead Se...

Megathrust earthquakes are commonly accompanied by increased upper‐plate seismicity and occasionally triggered fault slip. In Chile, crustal faults slipped during and after the 2010 Maule (M8.8) earthquake. We studied the El Yolki fault (EYOF), a transtensional structure midways the Maule rupture not triggered in 2010. We mapped a Holocene coastal...

Plain Language Summary Tsunami hazard assessment is routinely based on assessing the impacts of long‐period waves generated by vertical seafloor motions reaching the coast tens of minutes after the earthquake in typical subduction‐zone environments. This view is inadequate for assessing hazard associated with strike‐slip earthquakes such as the mag...

Climate-controlled lake level changes may exert a fundamental influence on the patterns of surface deformation, seismogenesis and fault activity. However, the relative contribution of climatic and tectonic factors on surface deformation at millennial time scales still remains poorly understood. The Dead Sea is the deepest continental basin on Earth...

Geomorphic strain markers accumulating the effects of many earthquake cycles help to constrain the mechanical behaviour of continental rift systems as well as the related seismic hazards. In the Corinth Rift (Greece), the unique record of onshore and offshore markers of Pleistocene ~100-ka climate cycles provides an outstanding possibility to const...

Subaqueous landslides are common features at active and passive ocean margins, in fjords and lakes. They can develop on very gentle slope gradients (<2°) and the presence of sandy tephra layers seems to facilitate the development of translational failure. Despite numerous investigations, it remains elusive how different slope preconditioning factor...

The morphology of marine and lacustrine terraces has been largely used to estimate past sea-and lake-level positions and vertical surface deformation; therefore, accurate assessments of terrace morphologies are important to obtain consistent estimates. TerraceM® provides new tools to analyze marine/lacustrine terraces by mixing high-resolution topo...

SINT-2: Sismotectónica, el ciclo de terremotos y paleosismología a lo largo del margen chileno The Pichilemu Fault is an extensional crustal structure located at the northern edge of the 2010 Maule Chile earthquake (M8.8). This structure was unknown until it generated two M6.9 and M7 shallow earthquakes 12 days after the Maule mainshock. However,...

Widespread sequences of uplifted marine terraces express multi-scale climatic and tectonic processes, but their analysis is typically biased by the considered sea-level curve. Here we explore the influence of Quaternary sea-level (SL) curves on the geometry of the marine terrace sequence at Xylokastro (Corinth Rift) using a numerical model of sea-c...

Assessments of megathrust earthquake rupture patterns provide fundamental insights into the processes that control the seismic cycle along subduction zones. When large earthquakes occur in regions with sparse geodetic networks, as was the case for the magnitude (⁠ Mw ⁠) 7.6 Chiloé, Chile, earthquake of 25 December 2016, estimates of vertical coseis...

The compound hazard effects of multiple process cascades severely affect Chilean river systems and result in a large variety of disturbances on their ecosystems and alterations of their hydromorphologic regimes leading to extreme impacts on society, environment and infrastructure. The acute, neo-tectonically pre-determined susceptibility to seismic...

Great megathrust earthquakes arise from the sudden release of energy accumulated during centuries of interseismic plate convergence. The moment deficit (energy available for future earthquakes) is commonly inferred by integrating the rate of interseismic plate locking over the time since the previous great earthquake. But accurate integration requi...

We present evidence of Holocene deformation along the northern Liquiñe-Ofqui Fault Zone (LOFZ). We studied four sites: Lonquimay, Palguín, Liquiñe and Maihue (A, B, C and D in Figure 1A). All the sites exhibit deformed tephra-bearing fluvial, glacial and lacustrine deposits. Tephra deposits were used to constrain the timing of deformation by correl...

In mid-2004, anthropogenically induced changes in water quality of the Río Cruces wetland, a Ramsar site located in southern Chile (ca. 40°S), enhanced the resuspension of iron-enriched sediments, which were subsequently deposited over the most abundant aquatic macrophyte of the wetland (Egeria densa Planch. 1849). This event triggered the formatio...

Fundamental processes of the seismic cycle in subduction zones, including those controlling the recurrence and size of great earthquakes, are still poorly understood. Here, by studying the 2016 earthquake in southern Chile—the first large event within the rupture zone of the 1960 earthquake (moment magnitude (Mw) = 9.5)—we show that the frictional...

In 2004 migration and mortality for unknown reasons of the herbivorous Black necked swan (Cygnus melancorhyphus (Molina, 1782)) occurred within the Río Cruces wetland (southern Chile), a Ramsar Site and nature sanctuary. Before 2004, this wetland hosted the largest breeding population of this water bird in the Neotropic Realm. The concurrent decrea...

The Tuz Gölü Basin is the largest sedimentary depression located at the center of the Central Anatolian Plateau, an extensive, low-relief region with elevations of ca. 1 km located between the Pontide and Tauride mountains. Presently, the basin morphology and sedimentation processes are mainly controlled by the extensional Tuz Gölü Fault Zone in th...

Geomorphic strain markers accumulating the effects of many earthquake cycles help to constrain the mechanical behaviour of continental rift systems as well as related seismic hazard. In the Corinth Rift (Greece), the remarkably rich record of onshore and offshore markers of Pleistocene 100ky climate cycles is unique worldwide and makes it a key sit...

A sandy beach-ridge plain, midway along the 1960 M9.5 Chile earthquake area, recorded a sequence of co-seismic subsidence events, and possible inter-seismic uplift, during the last millennium. Pangal plain is adjacent to Maullín and ~6 km west of Chuyaquen, where geologic evidence of seven earthquakes prior to 1960 was previously reported. The ~25...

En esta contribución presentamos evidencia clara de deformación Cuaternaria Tardía a lo largo del segmento norte del Sistema de Fallas Liquiñe-Ofqui (SFLO) entre los 38.5°S y 40°S (Fig. 1). Esta evidencia fue encontrada en cuatro sitios nombrados desde sur a norte como Lago Maihue, Liquiñe, Lago Caburgua y Lonquimay. En la periferia del lago Maihue...

On 25 December 2016, the Mw 7.6 Chiloé earthquake broke a plate-boundary asperity in South- Central Chile near the center of the rupture zone of the Mw 9.5 Valdivia earthquake of 1960. To gain insight on decadal-scale deformation trends and their relation with the Chiloé earthquake, we combine geodetic, teleseismic and regional seismological data....

Most of the deformation associated with the seismic cycle in subduction zones occurs offshore and has been therefore difficult to quantify with direct observations at millennial timescales. Here we study millennial deformation associated with an active splay-fault system in the Arauco Bay area off south central Chile. We describe hitherto unrecogni...

Coseismic tectonic deformation along the coasts of Cyprus is important to understand seismic hazard in the Eastern Mediterranean Region. Since the island is situated at the boundary between African and Eurasian plates it may provide information about major tectonic events. The presence of uplifted wave-cut platforms at the northern and eastern coas...

The April 1st 2014 Iquique earthquake (MW 8.1) occurred along the northern Chile margin where the Nazca plate is subducted below the South American continent. The last great megathrust earthquake here, in 1877 of Mw ~8.8 opened a seismic gap, which was only partly closed by the 2014 earthquake. Prior to the earthquake in 2013, and shortly after it...

Geographic locations of the sites where benchmarks were measured, mobile GPS stations were installed and geodesic data from continuous GPS stations located nearby our study sites were collected. (DOCX)