A computer-implemented method of hydrocarbon source rock characterization, comprising: a. receiving, at a computer processor, a seismic dataset representative of a subsurface volume of interest and a low frequency model of the subsurface volume of interest, wherein the seismic dataset contains frequencies in the range ~4-60 Hz and wherein the low frequency model contains frequencies in the range ~0-6 Hz; b. inverting, via the computer processor, the seismic dataset using the low frequency model to generate reservoir attributes; c. detrending, via the computer processor, the reservoir attributes by removing a depth-dependent compaction trend in the reservoir attributes to produce detrended reservoir attributes and the depth-dependent compaction trend; d. normalizing, via the computer processor, the detrended reservoir attributes with respect to the depth-dependent compaction trend to generate a trend-normalized reflectivity; and e. characterizing, via the computer processor, the hydrocarbon source rock based on the trend-normalized reflectivity, wherein the characterizing includes one or more of estimating TOC, source rock location, and source rock thickness and further comprises generating a 2-D or 3-D map of the hydrocarbon source rock representing the one or more of estimated TOC, source rock location, and source rock thickness, wherein TOC is Total Organic Content, and wherein: the seismic dataset is recorded seismic data from a seismic survey; and the method comprises designing well paths or designing drilling strategies or assessing hydrocarbon charge based on the generated 2-D or 3-D map. a. receiving, at a computer processor, a seismic dataset representative of a subsurface volume of interest and a low frequency model of the subsurface volume of interest, wherein the seismic dataset contains frequencies in the range ~4-60 Hz and wherein the low frequency model contains frequencies in the range ~0-6 Hz; b. inverting, via the computer processor, the seismic dataset using the low frequency model to generate reservoir attributes; c. detrending, via the computer processor, the reservoir attributes by removing a depth-dependent compaction trend in the reservoir attributes to produce detrended reservoir attributes and the depth-dependent compaction trend; d. normalizing, via the computer processor, the detrended reservoir attributes with respect to the depth-dependent compaction trend to generate a trend-normalized reflectivity; and e. characterizing, via the computer processor, the hydrocarbon source rock based on the trend-normalized reflectivity, wherein the characterizing includes one or more of estimating TOC, source rock location, and source rock thickness and further comprises generating a 2-D or 3-D map of the hydrocarbon source rock representing the one or more of estimated TOC, source rock location, and source rock thickness, wherein TOC is Total Organic Content, and wherein: the seismic dataset is recorded seismic data from a seismic survey; and the method comprises designing well paths or designing drilling strategies or assessing hydrocarbon charge based on the generated 2-D or 3-D map. the seismic dataset is recorded seismic data from a seismic survey; and the method comprises designing well paths or designing drilling strategies or assessing hydrocarbon charge based on the generated 2-D or 3-D map.