A system for finding oil deposits in ground based on a search for similar looking graphical features in graphs, comprising: one or more hardware computer processors configured to execute computer executable instructions in order to cause the system to: generate a first plurality of vectors that represent first sections of stored time series data comprising a number of data values, wherein the stored time series data are ground sonar readings from sensors at different locations and wherein the first plurality of vectors are generated by performing a mathematical transformation of the first sections of stored time series data to generate the first plurality of vectors, wherein respective vectors of the first plurality of vectors include coefficients whose number is smaller than the number of data values; transmit, to a user computer, data for displaying a graph of the first time series data; receive, from the user computer, an indication of a user selection of a section of the first time series data, wherein the user selection indicates one or more oil deposits; determine a first vector representing at least a first portion of the user-selected section of the first time series data, the first vector being generated by performing the mathematical transformation of the user-selected section of time series data to generate the first vector with a smaller number of coefficients than a quantity of data values of the first portion of the user-selected section; perform one or more comparisons to determine first candidate sections of the stored time series data that are similar to the user-selected section, the one or more comparisons including at least a first comparison of some of the first plurality of vectors against the first vector to determine first candidate sections of the stored time series data; perform a reverse transform of the mathematical transform of the first candidate sections to reconstruct an approximation of the data values of each candidate section using their vector data; compute a distance between data values of each reconstructed candidate section and the user selected section; provide at least one final candidate section, less than a number of first candidate sections, based at least in part of the calculated distances, wherein smallest distances indicate the closest looking graph sections; and transmit, for display on the user computer, results of the one or more comparisons, the results including an indication of the at least one final candidate section. generate a first plurality of vectors that represent first sections of stored time series data comprising a number of data values, wherein the stored time series data are ground sonar readings from sensors at different locations and wherein the first plurality of vectors are generated by performing a mathematical transformation of the first sections of stored time series data to generate the first plurality of vectors, wherein respective vectors of the first plurality of vectors include coefficients whose number is smaller than the number of data values; transmit, to a user computer, data for displaying a graph of the first time series data; receive, from the user computer, an indication of a user selection of a section of the first time series data, wherein the user selection indicates one or more oil deposits; determine a first vector representing at least a first portion of the user-selected section of the first time series data, the first vector being generated by performing the mathematical transformation of the user-selected section of time series data to generate the first vector with a smaller number of coefficients than a quantity of data values of the first portion of the user-selected section; perform one or more comparisons to determine first candidate sections of the stored time series data that are similar to the user-selected section, the one or more comparisons including at least a first comparison of some of the first plurality of vectors against the first vector to determine first candidate sections of the stored time series data; perform a reverse transform of the mathematical transform of the first candidate sections to reconstruct an approximation of the data values of each candidate section using their vector data; compute a distance between data values of each reconstructed candidate section and the user selected section; provide at least one final candidate section, less than a number of first candidate sections, based at least in part of the calculated distances, wherein smallest distances indicate the closest looking graph sections; and transmit, for display on the user computer, results of the one or more comparisons, the results including an indication of the at least one final candidate section.