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Climate-induced natural hazards are thought to be happening more frequent and more intense under an increasingly warmer Earth. Earth-observing satellites including the ones operate in constellations and deliver accurate and sub-daily high-resolution/stereo multispectral satellite imagery, provide an opportunity to rapidly monitoring and quantifying the magnitude of disasters. Planet PBC’s Dove/SuperDove, SkySat, RapidEye (retired in March 2020) satellite constellations have at present over 150 CubeSats providing daily/sub-daily sampled 0.5-5-meter resolution images globally. Here, we use the available multispectral images from Planet CubeSat constellations, other geodetic and remote sensing data with the objective to conduct a feasibility study to monitor hazards. In particular, our goal is to identify, track, and quantify the scopes of active wildfires and rapid flood events even at relatively small scales and relatively short-durations worldwide, to study the feasibility of using timely and multi-platform satellite observations to complement informed disaster responses. In this study, we provide case studies and demonstrations of example brush fire and flood hazards to examine the feasibility of a satellite observation-based decision-support disaster response and management tool., The 28th IUGG General Assembly (IUGG2023) (Berlin 2023)

On February 6, 2023, a sequence of earthquakes with Mw 7.8 and Mw 7.5 occurred in southern central Turkey near the northern border of Syria about in 9 hours. The disastrous earthquake sequence and its other aftershocks caused heavy human casualties and devastating building collapses. We employ the Empirical Orthogonal Function (EOF) analysis to capture coherent spatiotemporal features of co-seismic deformation for three components (N, E, U), which is based on the time series of 1-Hz GPS solutions at 20 permanent stations spatially well-distributed around the ruptured Anatolian fault system. The solved EOF modes show patterns which would help to investigate co-seismic rupture of the seismogenic faults. We compare the EOF-derived co-seismic displacement to the modeling results, which is computed from the spherical, elastic dislocation theory and finite fault model inverted from teleseismic waves records. Both GPS-observed and the modeled displacements show high consistency except for that at station EKZ1 (Ekinözü) where ~4.7 m of westward motion was estimated from GPS which we believe does not entirely represent the crustal motion; some other phenomena such as a local co-seismic landslide or a relative motion of the pillar with respect to the ground might have occurred. Moreover, this sequence is a large typical strike-slip faulting, which can generate gravity change above the threshold proposed by some theoretical simulation based on the satellite gravimetry observations. We also compute forward-modeled coseismic gravity changes, and discuss the plausible detection by instrument onboard of GRACE Follow-On gravimetry mission., The 28th IUGG General Assembly (IUGG2023) (Berlin 2023)

Starting from April 2002, Gravity Recovery and Climate Experiment (GRACE) and, its successor mission GRACE-FO (FollowOn) have provided irreplaceable data for monitoring mass variations within the hydrosphere, cryosphere, and oceans, and with unprecedented accuracy and resolution for over two decades. However, the long-term products of mass variations prior to GRACE-era may allow for a better understanding of spatiotemporal changes in climate-induced geophysical phenomena, including terrestrial water cycle, ice sheet and glacier mass balance, sea level change and ocean bottom pressure. In this study, total water storage anomalies (TWSA) are simulated/reconstructed globally at 1.0°x1.0° spatial and monthly temporal resolutions from January 1994 to December 2020 with an in-house developed hybrid Deep Learning (DL) architecture using GRACE/-FO mascon and SLR gravimetry, ECMWF Reanalysis-5 (ERA5) data. We validated our simulated mass change data products both over land and ocean, not only through mathematical performance metrics (internal validations) such as RMSE or NSE along with comparisons to previous studies, but also external validations with non-GRACE datasets such as El-Nino and La-Nina patterns, barystatic global mean sea level change, degree (d) 2 order (o) 1 spherical harmonic coefficients (C21, S21) retrieved from Earth orientation parameters, Greenland Ice sheet mass balance and in-situ Ocean Bottom Pressure measurements were carried out. The overall validations show that the proposed DL paradigm can efficiently simulate high-resolution monthly global gravity field both in GRACE/GRACE-FO and pre-GRACE era. The resulting simulated data products are available as monthly mass change grids as well as spherical harmonic models up to d/o 180., The 28th IUGG General Assembly (IUGG2023) (Berlin 2023)

JEODEZİK YÖNTEMLERLE DEFORMASYON ÖLÇMELERİ VE ANALİZİ ÖZET Büyük yapıların planlanması sırasında, yapının oturacağı zeminde yapıya zarar verebilecek olası yer kabuğu hareketlerinin saptanması, daha sonra çevrenin yapıya etkileri veya yükleme nedeniyle yapıda meydana gelebilecek geometrik şekil değişmelerinin saptanması veya yapının çevreye etkisiyle çevrede meydana gelebilecek değişimlerin saptanması ya da salt yeryüzü kabuk hareketlerinin belirlenmesi için yapılan jeodezik ölçmelere `deformayon ölçmeleri`, bu ölçülerin değerlendirilerek deformasyonların saptanması ve yorumlanmasına da `deformasyon analizi` adı verilmektedir. Bilindiği gibi yeryuvarı, içerisinde sürekli bir hareketlenmenin yaşandığı dinamik bir yapıya sahiptir. Bu hareketlerin sonucunda yeryüzünde meydana gelen yer ve şekil değiştirmelerin belirlenmesi, ve kritik değerlerin hesaplanarak olası felaketlere karşı önlemlerin alınması son derece önemlidir. Şimdiye kadar en çok kullanılan jeodezik deformasyon analizi yöntemi, iki farklı epok arasında deformasyon hızının sabit kaldığım kabul eden statik yöntemdir. Bunun en önemli nedeni, eskiden klasik aletlerle uzun süreli sürekli gözlem yapma olanağının bulunmaması idi. Fakat günümüzde, gelişen teknoloji ile birlikte jeodezicilerin hizmetine sunulan yeni ölçme donanımları artık bu zorunluluğu ortadan kaldırmış ve deformasyon ölçme ve analizinde yeni bir çağ başlatmıştır. Artık, deformasyonların büyüklüğü yanında hızı, ivmesi ve hatta ivmesinin zamana bağlı değişimi yüksek presizyonlu olarak belirlenebilmektedir. Özellikle, sistem tanımlamanın jeodeziye girmesi ile bu deformasyon hareketleri için modeller geHştirilmekte ve simulasyonlar yapılarak kritik değerler hesaplanıp bunlara karşı önlemler alınabilmektedir. Deformasyon analizi, beklenen deformasyonun türüne ve kullanılan jeodezik ağın tipine göre ardışık adımlar izlenerek yapılır. Eğer jeodezik ağ referans ve deformasyon noktalarından oluşuyorsa temel adımlar aşağıdaki gibi sıralanabilir:. Referans (sabit) noktaların incelenmesi ve hareketli olanların belirlenmesi. Deformasyon noktalarının noktasal hareketlerinin incelenmesi, bu noktaların ihmal edilmesi veya varsa yer değiştirmelerinin modellenmesi. Katı kitle hareketlerini ve cisim deformasyonlarını içeren deformasyon modelinin tasannu. Bu modelin istatistik testlerle gerçeklenmesi Fazla değişmemekle birlikte, deformasyon analizinde kullanılan yöntemler yukarıda belirtilen adımlar izlenerek yapılır. Bu çalışmada jeodezik yöntemlerle deformasyon analizinin yer bulduğu uygulama alanları, bu uygulama alanlarında kullanılan ölçme yöntemleri ve elde edilen ölçülerin değerlendirilmesinde kullanılan matematik modeller açıklanmıştır. Ayrıca bu matematik modeller karşılaştırılarak birbirlerine göre üstünlükleri, avantajları vedezavantaj lan açıklanmış ve hangi durumlarda hangi ölçme ve analiz yöntemlerinin kullanılacağı hakkında tavsiyelerde bulunulmuştur. Bu çalışmada, en eski yöntemlerden en güncel yöntemlere kadar, uygulamada kullanılan modelleme yöntemlerini bulmak mümkündür. Artık, bu ölçme ve matematik modellerden hangisinin kullanılacağı, yapılan çalışmanın amacına, deformasyona sebep olan parametrelerin bilinmesine ve eldeki ölçme donanımına bağlı olarak kullanıcı tararından belirlenecektir. DEFORMATION SURVEYS AND ANALYSIS BY GEODETIC METHODS SUMMARY The geodetic measurements performed to determine possible deformations to take place in the ground that the construction is located, to detect the effect of the construction and the possible displacements in the surroundings, and the geometric deformations on the construction as a result of loading on it and to determine just the crustal movements on the earth are called as `deformation measurements`, and the determination and the interpretation of the deformations through the evaluation of these measurements is named as `deformation analysis`. As it is known, the earth has a dynamic structure in which has a permanent activation. The determination of displacements and deformations occuring at the end of these movements, and taking precautions against possible disasters by calculating the critical values are strongly important. Up to now, the most frequently used geodetic deformation analysis method is the static method which assumes that the deformation velocity between two different epochs are constant. The most important reason of this was due to not being able to have possibility of long-term permanent observations by conventional surveying instruments in the past. But now, any more, with developing technology the new surveying instruments presented to the geodesists' usage has removed this obligation and started a new age in deformation surveys and analysis. Any more, beside the magnitude of deformations, their velocity, acceleration and even the change dependent time of the acceleration can be determined with high precision. Especially, with the entrance of system identification into geodesy, models for those deformation movements have been developed and precautions can be taken against, after calculation of critical values by simulations.. Screening of the reference points and elimination of unstable points.. Screening of the object points for single point movements, omission of the respective points or modelling of their displacements.. Design of a deformation model comprising rigid body movements and object deformations. » Verification of the model by statistical tests. With less modification, the methods used in deformation analysis are made by following steps mentioned above. In this study, application fields in which includes deformation analysis with geodetic methods, surveying techniques used in those application fields and the mathematical models used in evaluation of obtained data were described. Moreover, by comparing those mathematical models, their superiority, advantages and disadvantages have been explained and it was suggested in which cases, which surveying and analysis methods would be used.In this essay, it is possible to find modelling methods used in application from the oldest methods up to the most current techniques. Which of the surveying and mathematical model to be used, will be determined by user according to the goal of work, knowing the parameters causing deformations and available surveying instruments. Xll 84

In this study, application of Total Least Squares TLS method in deformation analysis and comparison of its results with the Least Squares LS method was aimed. In this context, GPS observations collected in a landslide area nearby BüyükçekmeceGürpinar landslide region in October 1997 and in March 1998 were processed. The deformations that took place in the region were then analysed by both LS and TLS methods and the results were interpreted., Bu çalışmada, Toplam En Küçük Kareler TEKK yönteminin deformasyon analizinde uygulanması, elde edilen sonuçların En Küçük Kareler EKK yöntemi ile deformasyon analiz sonuçları ile karşılaştırılması amaçlanmıştır. Bu nedenle BüyükçekmeceGürpınar heyelan bölgesinde Ekim 1997 ve Mart 1998’de gerçekleştirilen GPS gözlemleri değerlendirilmiş, bölgede meydana gelen deformasyonlar hem EKK hem de TEKK yöntemi ile analiz edilmiş ve elde edilen sonuçlar yorumlanmıştır.