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Wave hindcasts of long time series (>30 years) have been instrumental in understanding the wave climate. However, it is still difficult to have a consistent reanalysis suitable for study of trends and interannual variability. Here we explore the consistency of a wave hindcast with independent observations from moored buoys, satellite altimeters, and seismic data. We use the Climate Forecast System Reanalysis (CFSR) winds to drive a wave model since extreme events are generally well captured. Unfortunately, the original CFSR winds are not homogeneous in time. We systematically modify this wind field in time and space to produce a wave field that has homogeneous differences against the Globwave/SeaStateCCI altimeter wave height database. These corrections to the winds and resulting waves are validated using independent buoy and microseism data. We particularly use seismic data in the dominant double‐frequency band, around 5‐s period, that are generated by opposing waves of equal frequencies. The seismic data confirms that our correction of time‐varying biases is consistent, even in remote and undersampled region such as the Southern Ocean where the original CFSR biases are strongest. Our analysis is performed on monthly time series, and we expect the monthly statistics to be better suited for climate studies. Remaining issues with time consistency of reanalysis products and associated wave hindcasts are further discussed. Reanalysis products are not consistent in time due to changes in assimilated satellite data setsReanalysis winds speeds are corrected using wave height model‐altimeter residualsCloser agreement of trends between altimeter, hindcast, seismic, and buoy data sets is reached

For the first time, we measured the ellipticity of direct Rayleigh waves at intermediate periods (15–35 s) on Mars using the recordings of three large seismic Martian events, including S1222a, the largest event recorded by the InSight mission. These measurements, together with P‐to‐s receiver functions and P‐wave reflection times, were utilized for performing a joint inversion of the local crustal structure at the InSight landing site. Our inversion results are compatible with previously reported intra‐crustal discontinuities around 10 and 20 km depths, whereas the preferred models show a strong discontinuity at ∼37 km, which is interpreted as the crust‐mantle interface. Additionally, we support the presence of a shallow low‐velocity layer of 2–3 km thickness. Compared to nearby regions, lower seismic wave velocities are derived for the crust, suggesting a higher porosity or alteration of the whole local crust. As never before on Mars, we measured the characteristics of seismic waves traveling along the Martian surface that carry information about the crustal structure at the InSight site. We combined these measurements with two other local‐scale independent observations to derive a consolidated model for the crust underneath the InSight lander. Our results suggest a Martian crust with 4 layers and, particularly, one thin layer of about 2 km thickness close to the surface. The crust‐mantle discontinuity was found at ∼37 km depth, where the sharpest change in seismic wave velocity is observed. Overall, the seismic wave velocities of the local Martian crust at the InSight site are lower than those derived in other regions on Mars, which suggests a higher porosity or local alteration. Rayleigh waves ellipticity was measured between periods 15–35 s at the InSight landing site using large seismic events, including S1222aA 4‐layer crust, including a shallow low‐velocity layer, is required to explain the ellipticity, receiver functions and P‐wave lag timesLow crustal velocities are derived for the InSight site, which may be due to high porosity or heavy alteration at local scale Rayleigh waves ellipticity was measured between periods 15–35 s at the InSight landing site using large seismic events, including S1222a A 4‐layer crust, including a shallow low‐velocity layer, is required to explain the ellipticity, receiver functions and P‐wave lag times Low crustal velocities are derived for the InSight site, which may be due to high porosity or heavy alteration at local scale

Several characteristic waves detected by seismographs in Antarctic stations have been recognized as originating from the physical interaction between the solid earth and the atmosphere–ocean–cryosphere system surrounding the Antarctic and may be used as a proxy for characterizing ocean wave climate. A Chaparral-type infrasound sensor was installed at Syowa Station (SYO; 39.6E, 69.0S), East Antarctica, in April 2008 during the International Polar Year (IPY2007–2008). Matching data are also available for this time period from the existing broadband seismic recorder located close by. Continuous infrasound data for 2008–2009 include background signals (microbaroms) with a broad peak in the wave period between the values of 4 and 10 s. Signals with the same period are recorded by the broadband seismograph at SYO (microseisms). This period band is identified as double-frequency microseisms/baroms (DFM). The DFM have relatively lower amplitudes during winter. We suggest that this is due to the sea-ice extent around the coast causing a decreased ocean loading effect. In contrast, the single frequency microseisms/baroms with a peak in period between 12 and 30 s are observed under storm conditions, particularly in winter. On the infrasound data, stationary signals are identified with harmonic overtones at a few Hertz to lowermost human audible band, which we suggest is due to local effects such as sea-ice cracking and vibration. Microseism measurements are a useful proxy for characterizing ocean wave climate, complementing other oceanographic and geophysical data. At SYO, continuous monitoring by both broadband seismograph and infrasound contributes to the Federation of Digital Seismographic Networks, the Comprehensive Nuclear-Test-Ban Treaty in the high southern latitudes and the Pan-Antarctic Observations System under the Scientific Committee on Antarctic Research.

We describe the scientific purposes and experimental set-up of an international deployment of a 3 component broadband seismometer package on the ocean floor in Monterey Bay which took place during the summer of 1997. Highlights of this experiment were the installation, performed using a remotely operated vehicle (ROV), the underwater connection of the different components of the package, and the successful retrieval of 3 months of broadband seismic and auxiliary data. Examples of recordings of teleseisms and regional earthquakes are presented and the background noise characteristics are discussed, in comparison with those of near-by broadband land sites, current-meter data from the vicinity of the ocean bottom package, as well as pressure data from deeper ocean sites.