ggmap上的Geojson：第4层发生错误

我想通过ggmap在地图上显示来自URL的geojson文件。当我通过plot()绘制几何图形时，它就起作用了：

intensity_url <- "https://earthquake.usgs.gov/realtime/product/shakemap/us6000jllz/us/1675733020783/download/cont_mmi.json"
intensity <- geojson_read(data_url, what = "sp")
intensity <- sf::read_sf(intensity_url)

plot(intensity$geometry)

输出：

但是当我在ggmap上添加这个几何体时，它显示了一个错误：

bbox <- c(28.841667, 29.866555, 48.266738, 44.65)

myMap <- get_stamenmap(bbox=bbox)

ggmap(myMap) +
  geom_sf(aes(long, lat, group = group), data = intensity$geometry)

错误消息：

ℹ Map tiles by Stamen Design, under CC BY 3.0. Data by OpenStreetMap, under ODbL.
ℹ 3024 tiles needed, this may take a while (try a smaller zoom?)
Warning: Ignoring unknown aesthetics: x and yCoordinate system already present. Adding new coordinate system, which will replace the existing one.Error in `geom_sf()`:
! Problem while computing aesthetics.
ℹ Error occurred in the 4th layer.
Caused by error in `FUN()`:
! object 'group' not found
Backtrace:
  1. base (local) `<fn>`(x)
  2. ggplot2:::print.ggplot(x)
  4. ggplot2:::ggplot_build.ggplot(x)
  5. ggplot2:::by_layer(...)
 12. ggplot2 (local) f(l = layers[[i]], d = data[[i]])
 13. l$compute_aesthetics(d, plot)
 14. ggplot2 (local) compute_aesthetics(..., self = self)
 15. ggplot2:::scales_add_defaults(...)
 16. base::lapply(aesthetics[new_aesthetics], eval_tidy, data = data)
 17. rlang (local) FUN(X[[i]], ...)
Error in geom_sf(aes(long, lat, group = group), data = intensity$geometry) :

ℹ Error occurred in the 4th layer.
Caused by error in `FUN()`:
! object 'group' not found

注意：当我从aes中删除group时，它将显示相同的错误，并带有long。

您知道为什么显示此错误吗？