Which of the following is not classified as a somatic mode of death?

Rubor, which refers to redness of the skin, is not classified as a somatic mode of death. Somatic modes of death typically involve physiological processes or external factors that result in the cessation of life. Asphyxia involves a lack of oxygen leading to death, accidental trauma refers to physical injuries leading to death, and cardiac arrest involves the heart's failure to pump blood, ultimately resulting in death.

Rubor, on the other hand, is a clinical sign indicating increased blood flow to an area, often due to inflammation or injury, but it does not directly pertain to the actual processes or mechanisms that cause death. Hence, it does not fit into the classification of somatic modes of death.