Job 9:5 Which removeth the mountains, and they know not: which overturneth them in his anger.
God is the only one that can shake the earth. An earthquake is a manifestation of God's anger. As human beings, we could sometimes be angry. God also has the right to be angry.
Why does God get angry?
God get angry because He hates ungodliness and unrighteousness. Our ungodly characters and deed could make God angry with us. As God can be angry, he is also slow according to the Bible. If you would consider the ungodliness and unrighteousness in the world today, it possible that he would have destroyed the entire earth. But God merciful and slow to anger. We are to blame God for any death.
Romans 1:18 For the wrath of God is revealed from heaven against all ungodliness and unrighteousness of men, who hold the truth in unrighteousness;
Psalms 103:8 The LORD is merciful and gracious, slow to anger, and plenteous in mercy.