Daly City-area historical earthquake activity is near California state average. It is 735% greater than the overall U.S. average. On 4/18/1906 at 13:12:21, a magnitude 7.9 (7.9 UK, Class: Major, Intensity: VIII - XII) earthquake occurred 36.2 miles away from the city center, causing $524,000,000 total damage.
(Äd-hÄ'zhÉn) 1  The force of attraction that causes two different substances to join. Adhesion causes water to spread out over glass. 2  A fibrous band of abnormal tissue that binds together tissues that are normally separate. Adhesions form during the healing of some wounds, usually as a result of inflammation.
Chemical adhesion occurs when the surface atoms of two separate surfaces form ionic, covalent, or hydrogen bonds. The engineering principle behind chemical adhesion in this sense is fairly straightforward: if surface molecules can bond, then the surfaces will be bonded together by a network of these bonds.