We present an exceptionally long and continuous coastal lacustrine record of ~5500 years from Lake Huelde on the west coast of Chiloé Island in south central Chile. The study area is located within the rupture zone of the giant AD 1960 Great Chilean Earthquake (M W 9.5). The subsequent earthquake-induced tsunami inundated Lake Huelde and deposited mud rip-up clasts, massive sand and a mud cap in the lake. Long sediment cores from 8 core sites within Lake Huelde reveal 16 additional sandy layers in the 5500 year long record. The sandy layers share sedimentological similarities with the deposit of the AD 1960 tsunami and other coastal lake tsunami deposits elsewhere. On the basis of general and site-specific criteria we interpret the sandy layers as tsunami deposits. Age-control is provided by four different methods, 1) 210 Pb-dating, 2) the identification of the 137 Cs-peak, 3) an infrared stimulated luminescence (IRSL) date and 4) 22 radiocarbon dates. The ages of each tsunami deposit are modelled using the Bayesian statistic tools of OxCal and Bacon. The record from Lake Huelde matches the 8 regionally known tsunami deposits from documented history and geological evidence from the last ~2000 years without overor underrepresentation. We extend the existing tsunami history by 9 tsunami deposits. We discuss the advantages and disadvantages of various sedimentary environments for tsunami deposition and preservation, e.g. we find that Lake Huelde is 2 to 3 times less sensitive to relative sea-level change in comparison to coastal marshes in the same region.

Historical and paleoseismic records in south-central Chile indicate that giant earthquakes on the subduction megathrust −such as in AD1960 (M w 9.5)− reoccur on average every ~300 years. Based on geodetic calculations of the interseismic moment accumulation since AD1960, it was postulated that the area already has the potential for a M w 8 earthquake. However, to estimate the probability of such a great earthquake to take place in the short term, one needs to frame this hypothesis within the longterm recurrence pattern of megathrust earthquakes in south-central Chile. Here we present two long lacustrine records, comprising up to 35 earthquake-triggered turbidites over the last 4800 years. Calibration of turbidite extent with historical earthquake intensity reveals a different macroseismic intensity threshold (≥VII½ vs. ≥VI½) for the generation of turbidites at the coring sites. The strongest Highlights  Multi-threshold turbidite paleoseismic records in south-central Chilean lakes  Probability estimates for M w ≥ 7.7 and M w ≥ 8.6 megathrust earthquakes  Quasi-periodicity suggests a dominant role for a large megathrust asperity

High-arctic fjords, for example, van Keulenfjorden on Spitsbergen, provide valuable palaeoenvironmental archives as they typically contain landforms and sediment sequences that document past changes in glacial activity with high temporal resolution. Van Keulenfjorden was covered with a grounded glacier during the last glacial, and it was deglaciated between c. 11.8 and 11.3 cal. ka BP. The retreat of the ice front accelerated from approximately 80 to 190 m/a during the deglaciation. The maximum late Holocene glacier extent occurred after surge-like advances of the glacier Nathorstbreen between 2790 and 2610 cal. yr BP (i.e. during a period with the coldest climatic conditions on Svalbard). This maximum extent was reached approximately 2600 years earlier than inferred for most fjords on Svalbard, suggesting that surge-like glacier advances on Svalbard can occur under variable climatic conditions. The time interval between the advances of Nathorstbreen around 2.7 ka BP was approximately 100–150 years. This is comparable to the last and only historically known quiescent phase of Nathorstbreen of c. 120 years between the late 19th century and the most recent surge from 2003 to 2012

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