library(ggplot2) # membuat plot statis 
library(ggpubr) # export plot statis
library(scales) # mengatur skala plot
library(glue) # setting teks pada tooltip
library(plotly) # membuat plot interaktif
library(dplyr)
library(lubridate)
library(flexdashboard)
library(tidyverse)
library(plotly)
library(leaflet)
library(leafgl)
library(sf)
library(colourvalues)
library(highcharter)
library(chron)
library(viridis)
library(shiny)
library(DT)

#Introduction

Indonesia is an Archipelago country which is crossed by many of the earth’s tectonic plates. Those tectonic plates potentially raises earthquakes caused by the movement of tectonic plates which is happened everyday. But, not all those earthquakes could be felt by human due to its magnitudes, central location, and depth of the earthquakes from human settlement.

World’s three main tectonic plates crossed Indonesia, it is Indo-Australia, Pacific, and Eurasia.

knitr::include_graphics("peta tektonik indonesia.jpg")

1 Data Pre-Processing

  • Change data type strings to factor
  • filter unnecessary colomns
  • change data type to date
earthquakes <- read.csv("katalog_gempa.csv")

earthquakes2 <- earthquakes %>% 
           select(-c(8:13)) %>% 
           mutate(ot = as.factor(ot)) %>% 
           mutate(tgl = mdy(tgl)) %>% 
           mutate(remark = as.factor(remark)) %>% 
           mutate(label = glue(
             "Magnitude: {mag}
              Region: {remark}"
           )) %>% 
           mutate(label2 = glue(
             "Depth: {depth}
              Region: {remark}"
           )) %>% 
           arrange(-mag)
  
earthquakes2

1.1 Check missing Value

earthquakes2 %>% is.na() %>% colSums()
#>    tgl     ot    lat    lon  depth    mag remark  label label2 
#>      0      0      0      0      0      0      0      0      0

1.1.1 Insight : There is no missing value in the data set

#Plot 1 ## Scatter Plot of Magnitude

plot(x = earthquakes2$mag, y = earthquakes2$tgl,
     col = earthquakes2$remark,
     pch = 19
     )

abline(lm(earthquakes2$tgl ~ earthquakes2$mag))

###Insight : Most of the earthquake magnitude occured in 2008-2023 is ranging bigger than 2 and smaller than 6

#Plot 2 ## Bar Plot of Magnitude

plot2 <- ggplot(data = earthquakes2,
                aes(x = mag, 
                    y = reorder(remark, mag),
                    text = label )) +
geom_col(aes(fill = mag )) +
  scale_fill_gradient(low = "blue", high = "green") +
  labs(title = "Earthquakes in Indonesia 2008-2023",
       x = "Frequency of Earthquakes",
       y = NULL) +
  theme_minimal()   

ggplotly (plot2, tooltip = "text")

###Insight : Most top 3 frequent region got earthquake is Sumatra, Java, and Minahasa Peninsula

#Plot 3 ## Scatter Plot of Depth

plot(x = earthquakes2$depth, y = earthquakes2$tgl,
     col = earthquakes2$remark,
     pch = 19
     )

abline(lm(earthquakes2$tgl ~ earthquakes2$depth))

###Insight : Most earthquake were occured at the depth between 2 km until 200 km under the ground

#Interactive Map

map <- leaflet()
map <- addTiles(map)
map <- 
  addCircleMarkers(
    lat = earthquakes2$lat,
    lng = earthquakes2$lon,
    map = map,
    weight = 0.1,
    radius = sqrt(earthquakes2$mag),
    opacity = 0.7,
    color = palette(),
    popup = paste("Depth: ", earthquakes2$depth, "Magnitude: ", earthquakes2$mag, "Region: ", earthquakes2$remark))
  
map