Observed surges and results from k-means and inversions. Columns from left to right: radiance maps in the core of the Mg II k 2796.3 Å line; cluster labels from the k-means ordered by the amount of profiles within a cluster; and maps at log₁₀(τ) = − 5.2 for temperature, T, electron number density, n_e, and LOS velocity, V_LOS, from the inversions of the Mg IIh&k line using the STiC code. Black contours delimit the bulk of the surges visible in the Mg II k 2796.3 Å radiance maps. Bad pixels and pixels affected by cosmic rays are masked and shown with a color gray. Colored diamonds are superimposed in the first panel for later reference. An animation of this figure is available online varying log₁₀(τ) from −6.0 to −3.2.