Reference Earth model: heat-producing elements & geoneutrino flux *Yu Huang, Roberta Rudnick, and Bill McDonough Geology, U Maryland *Slava Chubakov, Fabio Mantovani Physics, U Ferrara, Italy

Geoneutrino Flux on Earth Surface Earth structure (  and L) and chemical composition (a) Activity and number of produced geoneutrinos Volume of source unit Survival probability function Distance between source unit and detector

Constructing a 3-D reference model Earth assigning chemical and physical states to Earth voxels 1 o x 1 o x “z” tile mapping of elements Huang et al (2013) G-cubed arXiv: arXiv:

Global Earth Reference Model -7 layers for the top 200 km -Integrate 3 global models for the crust -New crust model with uncertainties Huang et al (2013) G-cubed

Global Earth Reference Model -7 layers for the top 200 km -Integrate 3 global models for the crust -New crust model with uncertainties Huang et al (2013) G-cubed

Defining Crustal Thickness: 3 models  Refraction and Reflection seismic waves: CRUST  Surface seismic waves: CUB  Gravitational potential field and gradiometer: GEMMA 3 1 Bassin et al., Shapiro and Ritzwoller, Negretti et al., 2012

Defining Uncertainties Crustal Thickness  ~10% uncertainty in continents  Larger uncertainty in oceans and continental margins  First uncertainty estimate of global crustal thickness!

Seismic Velocities of Deep Crustal Rocks Linear relationship (Vp vs. SiO 2 ) Two components mixing in MC and LC: felsic and mafic SiO 2 (wt. %) Middle CC

Seismic Velocities of Deep Crustal Rocks Two components mixing in MC and LC: felsic and mafic Distinguishable by Vp (1-sigma) Close to linear relationship (Vp vs. SiO 2 ) SiO 2 (wt. %) Amphibolite Granulite

Non-Gaussian distributions Uranium Abundance Composition of Mafic & Felsic Components

How to Track Uncertainty? Monte Carlo simulation : highly desired for the propagation of asymmetric uncertainties Requirement : the PDFs of all inputs are known Generate random samples for inputs, including correlation Calculate output variables Statistical analysis

Uranium Abundance in Middle Continental Crust layer Average middle Cont. Crust U abundance is  g/g Rudnick and Gao (2003) 1.3  g/g U MCC (  g/g)

Uranium Abundance in Lower Continental Crust layer Average lower Cont. Crust U abundance is  g/g U LCC (  g/g)

Upper crust Middle crust Lower crust Upper mantle ~35km Geological model – Continental Crust Moho Surfaces of each layer is defined by geophysical data (i.e., gravity and seismic) crust – mantle boundary U (ppm)

Predicted Global geoneutrino flux based on our new Reference Model Huang et al (2013) G-cubed arXiv: arXiv: /ggge /ggge Geoneutrino detection rate --TNU: Terrestrial Neutrino Unit -- 1 TNU = one geoneutrino event per free protons per year

Near Field: six closest 2° × 2° crustal voxels Far Field = bulk crust – near field crust

What’s hidden in the mantle? Seismically slow “red” regions in the deep mantle Can we image it with geonus? Ritsema et al (Science, 1999)

Testing Earth Models Mantle geoneutrino flux ( 238 U & 232 Th) Šrámek et al (2013) EPSL /j.epsl ; arXiv: /j.epsl arXiv:

Predicted geoneutrino flux Mantle flux at the Earth’s surface Šrámek et al (2013) EPSL /j.epsl ; arXiv: /j.epsl arXiv: Yu Huang et al (2013) G-cubed arXiv: arXiv: /ggge Total flux at surface dominated by Continental crust dominated by deep mantle structures

Geology input Physics input

Geology input Physics input

Physics input Geology input

SNO+ Hanohano Physics input Geology input