Suppose that the angular velocity of rotation of earth is increased. Then, as a consequence

Effect of rotation of earth on acceleration due to gravity is given by  $g\text{'}=g-R{\omega }^2{\cos }^2\varphi$
Where $\varphi$  is the latitude angle. There will be no change in gravity at poles because $\varphi =90°$  at the poles and at all other points as $\omega$  increases, $g\text{'}$  will decrease.