How do sea-level curves influence modeled marine terrace sequences?

Abstract

a b s t r a c tSequences of uplifted marine terraces are widespread and reflect the interaction between climatic and tectonic processes at multiple scales, yet their analysis is typically biased by the chosen sea-level (SL) curve. Here we explore the influence of Quaternary SL curves on the geometry of marine terrace sequences using landscape evolution models (LEMs). First, we modeled the young, rapidly uplifting sequence at Xylokastro (Corinth Rift; <240 ka;~1.5 mm/yr), which allowed us to constrain terrace ages, model parameters, and best-fitting SL curves. Models that better reproduced the terraced topography used a glacio-isostatically adjusted SL curve based on coral data (for~125 ka), and a eustatic SL curve based on ice-sheet models (for~240 ka). Second, we explored the opposite end-member of older, slower uplifting sequences (2.6 Ma; 0.1e0.2 mm/yr). We find that cliff diffusion is important to model terrace sequence morphology, and that a hydraulic-model based SL curve reproduced observed terrace morphologies best. Third, we modeled the effect of SL noise with various amplitudes and wavelengths on our interpretations, finding that younger, faster uplifting sequences are less noise-sensitive and thus generally more promising for LEM studies. Our results emphasize the importance of testing a variety of SL-curves within marine terrace studies, and highlight that accurate modeling through LEMs may provide valuable insight on climatic and tectonic forcing to Quaternary coastal evolution.

Variable Quaternary Uplift Along the Southern Margin of the Central Anatolian Plateau Inferred From Modeling Marine Terrace Sequences

“…where E is the terrace elevation and e the sea level at the moment of marine terrace formation and T the age of the terrace (Lajoie, 1986). Nevertheless, uplift rates that include a correction for eustatic sea level might be biased by the uncertainties in the chosen sea-level curve (e.g., de Gelder et al, 2020;Pedoja et al, 2014;Yildirim et al, 2013). Beyond this simplistic approach to calculate uplift rates, temporal variations in uplift rates might produce cumulative vertical displacements that may be difficult to estimate using equation 2, as they depend on the vertical position of the markers before the change of uplift take place.…”

Quaternary E‐W Extension Uplifts Kythira Island and Segments the Hellenic Arc

“…We use the cliff erosion model in TerraceM (Jara‐Muñoz et al., 2019 ; adapted from Anderson et al., 1999 ), with standard parameter values for wave height (4 m), erosion rate (0.5 m/yr) and an initial slope based on the approximate slope of the sequence (12°). For simplicity, and to avoid biased results by sea‐level noise inherent to long‐term (>1 Ma) sea‐level curves (de Gelder et al., 2020 ), we approximate Quaternary sea‐level by combining a 40 ky‐period, 65 m‐amplitude sine function (2.6–1 Ma) and a 100 ky‐period, 130‐m amplitude sine function (Figure 9b ). Additional tests with different parameter values and published Plio‐Quaternary sea‐level curves are given in Figure S5 of Supporting Information S1 , and do not change the main modeling outcomes.…”

“…(a) Different vertical motion scenarios, with scenario 1 assuming 400 m of rapid uplift followed by 200 m of slow uplift, as suggested by Van Hinsbergen et al (2006), and scenarios 2, 3 and 4 assuming the dated samples of this study are equivalent to maximum transgression at ∼2.6 Ma, and either steady slow uplift since then (scenario 2), a slow uplift followed by a rapid uplift (scenario 3 -uplift rate 0.22 mm/yr as estimated in Figure8) or stable conditions followed by a rapid uplift (scenario 4 -uplift rate 0.37 mm/yr as estimated in Figure8). (b) Extremely simplified sea-level curve used for the modeling (followingde Gelder et al, 2020). (c) Modeling results for the different scenarios, compared to the terraced topography as given in Figure8.…”

Causes of permanent vertical deformation at subduction margins: Evidence from late Pleistocene marine terraces of the southern Hikurangi margin, Aotearoa New Zealand

“…As we are constrained by the available preservation of marine terraces, and that, the terraces at the sites used to constrain our models are of different ages (MIS 5a, 5c and 5e), in this investigation it is necessary to assume that uplift rates have been constant across the southern Hikurangi Margin since the late Pleistocene. This assumption is widespread in studies that aim to constrain uplift rates by matching terrace elevations to sea-level curves (e.g., Pedoja et al, 2006;Authemayou et al, 2017;Jara-Munoz et al, 2017;De Gelder et al, 2020), but has been challenged by Mouslopoulou et al (2016) and McKenzie et al (2022). We prefer the assumption of constant uplift rates to alternative approaches-such as attempting to fit uplift of an inferred MIS 5e terrace in places where there are no direct dating constraints-for two reasons.…”