svgclip.svg

<svg version="1.1" xmlns="http://www.w3.org/2000/svg" xmlns:xlink="http://www.w3.org/1999/xlink" >
    <defs>
        <rect id="canvas" width="100%" height="100%" fill="white" />
        <circle id="shape1" cx="100" cy="100" r="100" />
        <rect id="shape2" x="0" y="100" width="200" height="100" fill="white" />
            <mask id="half-circle">
            <use href="#canvas"  />
            <use href="#shape1"  />
            <use href="#shape2"  />
        </mask>
    </defs>
    
      <g fill="grey"
     transform="rotate(-10 50 100)
                translate(50 45.5)">
    <circle cx="100" cy="100" r="100" fill="#044B94" fill-opacity="0.4"/>
    <ellipse cx="100" cy="100" rx="110" ry="50" 
      style="fill: none; stroke: cadetblue; stroke-width: 10;" mask="url(#half-circle)"/>
  </g>

</svg>