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Earths surface isn't just dirt and rock. It features majestic mountains and verdant valleys, rolling rivers and violent volcanoes. Readers are whisked away on a tour of the planet and it's many fascinating landforms. They will see many of Earth's most interesting natural locations and learn how they were formed.

The 2023 M.sub.w 7.6 Turkey earthquake was a crustal mega-earthquake that caused severe damage and loss of life. However, previous slip models based on kinematic source inversion or back-projection are not applicable to simulate or predict strong ground motions in the full frequency range of engineering interest. In this study, a characterized source model of the 2023 M.sub.w 7.6 Turkey earthquake was estimated by the empirical Green's function method using near-field strong motion records over a frequency range of 0.2-10 Hz. Among five strong motion generation areas (SMGAs) of the estimated model, the one with the largest Brune stress drop of 24.2 MPa was close to the large slip area estimated by previous slip models. Another SMGA was located near the fault bend, and two more SMGAs were located near the end of the faults where off-fault deformation was large. In both locations, the slip was not as large as in previous models. The off-fault damage may have facilitated high-frequency motion near the end of the fault. It is also conceivable that the fault bend acted as a geometric barrier, generating high-frequency ground motions. Bilateral supershear rupture was estimated to occur on both sides of the hypocenter. Short-period spectral level, which is the constant value of the acceleration source spectrum higher than the corner frequency, was larger than the previous scaling relations and data of five M.sub.w > 7.4 crustal mega-earthquakes, including the 2023 M.sub.w 7.8 Turkey earthquake. The combined area of the SMGAs were comparable to them. These results indicate that the M.sub.w 7.6 Turkey earthquake generated more high-frequency motions compared to previous crustal mega-earthquakes. The short-period spectral level and the combined area of the SMGAs of the M.sub.w 7.6 Turkey earthquake estimated in this study will be useful to improve their scaling relations of crustal mega-earthquakes for strong motion prediction.

Earth exhibits a dichotomy in elevation and chemical composition between the continents and ocean floor. Reconstructing when this dichotomy arose is important for understanding when plate tectonics started and how the supply of nutrients to the oceans changed through time. We measured the titanium isotopic composition of shales to constrain the chemical composition of the continental crust exposed to weathering and found that shales of all ages have a uniform isotopic composition. This can only be explained if the emerged crust was predominantly felsic (silica-rich) since 3.5 billion years ago, requiring an early initiation of plate tectonics. We also observed a change in the abundance of biologically important nutrients phosphorus and nickel across the Archean-Proterozoic boundary, which might have helped trigger the rise in atmospheric oxygen.

The rock record and geochemical evidence indicate that continental recycling has been occurring since the early history of the Earth. The stabilization of felsic continents in place of Earth’s early mafic crust about 3.0 to 2.0 billion years ago, perhaps due to the initiation of plate tectonics, implies widespread destruction of mafic crust during this time interval. However, the physical mechanisms of such intense recycling on a hotter, (late) Archaean and presumably plate-tectonic Earth remain largely unknown. Here we use thermomechanical modelling to show that extensive recycling via lower crustal peeling-off (delamination but not eclogitic dripping) during continent–continent convergence was near ubiquitous during the late Archaean to early Proterozoic. We propose that such destruction of the early mafic crust, together with felsic magmatism, may have caused both the emergence of silicic continents and their subsequent isostatic rise, possibly above the sea level. Such changes in the continental character have been proposed to influence the Great Oxidation Event and, therefore, peeling-off plate tectonics could be the geodynamic trigger for this event. A transition to the slab break-off controlled syn-orogenic recycling occurred as the Earth aged and cooled, leading to reduced recycling and enhanced preservation of the continental crust of present-day composition. The processes for crustal recycling during the Archaean are unclear. Numerical simulations suggest that dense lower crust would have peeled off into the mantle, leading to a rapid concentration of buoyant silicic rocks that formed the continents.

Planetary Crusts explains how and why solid planets and satellites develop crusts. Extensively referenced and annotated, it presents a geochemical and geological survey of the crusts of the Moon, Mercury, Venus, Earth and Mars, the asteroid Vesta, and several satellites like Io, Europa, Ganymede, Titan and Callisto. After describing the nature and formation of solar system bodies, the book presents a comparative investigation of different planetary crusts and discusses many crustal controversies. The authors propose the theory of stochastic processes dominating crustal development, and debate the possibility of Earth-like planets existing elsewhere in the cosmos. Written by two leading authorities on the subject, this book presents an extensive survey of the scientific problems of crustal development, and is a key reference for researchers and students in geology, geochemistry, planetary science, astrobiology and astronomy.

Constructed on one continuous folded page, this book explores the layers of the Earth from human-made structures like sewers, subways, and archeological finds, down through various formations of rock, to the Earth's core and back up again.

NW Canada and Alaska are the continuation of the North American Cordillera through Mexico, western USA and western Canada. I show that they have similar thermal regimes and thermal control of tectonics and seismicity. I first summarize the multiple constraints to crust and upper mantle temperatures and then discuss some consequences. There are bimodal crust and upper mantle temperatures characteristic of most subduction zones: cool forearc, uniformly hot backarc (Yukon Composite Terrane to Southern Brooks Range, and Mackenzie Mountains), and stable cratonic backstops (Arctic Alaska Terrane and Canadian Shield). The main constraints are as follows: (a) Heat flow measurements, (b) Temperature‐dependent upper mantle velocities and seismic attenuation, (c) Temperature‐dependent topographic elevations; thermal isostasy, (d) Depth and temperature of the seismic lithosphere‐asthenosphere boundary (LAB), (e) Origin temperature and depth of craton kimberlite xenoliths, (f) Geochemically inferred source temperature and depth of recent volcanic rocks. (g) Depth to the magnetic Curie temperature, (h) Depth extent of seismicity. The backarc lithosphere is thin, LAB at 50–85 km and ∼1,350°C ± 25°C. Moho temperatures at 35 km are 850°C ± 100°C compared to cool cratonic areas of 400°C–500°C. The consequences include the following: (a) Thin and weak backarc lithosphere that accommodates pervasive tectonic deformation indicated by wide‐spread seismicity and GPS‐defined motions, in contrast to the stable cratonic regions; (b) Weak backarc lower crust that flattens the Moho and allows detachment and thrusting of the upper crust over the cold strong Arctic Alaska Terrane and Canadian Shield. This article provides a model for how to estimate deep temperatures from multiple constraints. Plain Language Summary Alaska and NW Canada are the continuation of the North American Cordillera mountain belt through Mexico, western USA and western Canada. I show that they have similar high temperatures in the earth's crust and upper mantle, and that these deep temperatures are the principal control of earthquake occurrence and ongoing mountain belt deformation processes. Hot crustal areas are weak and deform easily, whereas cold strong areas like the Canadian Shield deform very little and have fewer earthquakes. I first outline the constraints to deep earth temperatures in Alaska and NW Canada and then the earthquake and mountain building consequences. The key association in this region and globally is that there are uniformly high crustal temperatures in the weak “backarcs,” the high mountain belts that extend 100 s of kilometers landward of current and recent subduction zones (where ocean crust is being thrust beneath continents generating volcanoes, and great earthquakes). I summarize eight methods that provide estimates of deep temperatures. They give a consistent picture, with deep temperatures in the backarc mountain belts of central Alaska, the Yukon and western Northwest Territories that are double those in the cold strong cratons (shields) of the northern part of arctic Alaska and the Canadian Shield in NW Territories. Earthquakes and mountain building processes follow this deep temperature difference, with most occurring where crustal temperatures are high and the crust weak. Key Points The regional distribution of seismicity and tectonic deformation in Alaska/NW Canada is controlled by crust and upper mantle temperatures Eight principal constraints are presented that give consistent deep temperature estimates; bimodal factor of two, backarc versus craton 300–800 km wide Cordillera backarc is uniformly hot and tectonically active in contrast to the cold stable Arctic Alaska and Canadian Shield