The city council may provide for the appointment of a board of appeals consisting of five regular members. Two additional alternate members shall be appointed and designated as first alternate and second alternate members, either or both of whom may attend any meeting and may serve as voting and participating members of the board with the authority of a regular board member at any time when less than the full number of regular board members is present and capable of voting. If both alternate members are present when only a single regular member is absent, the first alternate member shall serve for the balance of the meeting. Upon the expiration of the initial terms of such regular and alternate members, all members and alternates shall be appointed for a term of five years. The appointing authority shall have the power to remove any regular or alternate member of the board for cause and after public hearing. Vacancies shall be filled for the unexpired term of a regular or alternate member whose place has become vacant. All meetings of the board of appeals shall be held at the call of the chairperson and at such other times as such board may determine. Such chairperson, or in his or her absence the acting chairperson, may administer oaths and compel the attendance of witnesses. All meetings of such board shall be open to the public. Such board shall keep minutes of its proceedings, showing the vote of each member upon every question, or if absent or failing to vote, indicating such fact, and shall also keep records of its examinations and other official actions. Every rule or regulation, every amendment or repeal thereof, and every order, requirement, decision, or determination of the board shall immediately be filed in the office of the board and shall be a public record.