31:T499,Plot.plot({ marks: [ Plot.dot( localizedData .filter((t) => t.datetime < scrubTime2) .filter((t) => t.depth < 10), { x: (d) => projectOntoAxis(d.lat, d.lon), y: "depth", stroke: "datetime", strokeWidth: 1, r: (d) => eqRadius(d.magnitude) } ), Plot.ruleY([0]), Plot.ruleY([7], { strokeDasharray: [4, 10] }), Plot.text( [ [0.2, "Surface"], [6.5, "Upper Crust"], [7.5, "Middle Crust"] ], { x: d3.extent(localizedData, (d) => projectOntoAxis(d.lat, d.lon))[ angle <= 250 && angle >= 71 ? 1 : 0 ], y: (d) => d[0], text: (d) => d[1], textAnchor: "start", fontWeight: "bold" } ) ], y: { reverse: true, domain: [0, 10] }, r: { type: "identity" }, x: { reverse: angle <= 250 && angle >= 71, domain: d3.extent(localizedData, (d) => projectOntoAxis(d.lat, d.lon)), // axis: false, label: directionLabelMap(angle), ticks: 0, labelAnchor: "center" }, marginLeft: 20, marginRight: 0, width: d3.max([width, 500]), height: 450 })32:[{"id":"0c83e25327fe846e736a19b566d387daee83f50d2e4bc77763c0d174687b2e71409ccd6f2dafe76095abfba013b9ac38ca01beb6ec71cfb4ea438d351f70c67c","href":"https://static.observableusercontent.com/files/0c83e25327fe846e736a19b566d387daee83f50d2e4bc77763c0d174687b2e71409ccd6f2dafe76095abfba013b9ac38ca01beb6ec71cfb4ea438d351f70c67c","name":"Icelandic Earthquakes.csv","type":"text/csv","lastModified":1699845059612.104,"size":378202}] 2f:{"title":"Exploring Icelandic Earthquakes","cells":[{"id":0,"value":"# Exploring Icelandic Earthquakes","pinned":false,"hidden":false,"mode":"md"},{"id":581,"value":"Since Friday November 10th, Iceland has experiencing a significant increase in seismic activity in the southwest of the island, and local authorities believe a [volcanic eruption is imminent](https://www.cnn.com/2023/11/11/europe/iceland-emergency-evacuates-threat-volcanic-eruption-intl-hnk/index.html). \n\nEarthquakes provide useful signals to where and when this eruption might occur. In this notebook I explore 4,663 earthquakes since activity increased.","pinned":false,"hidden":false,"mode":"md"},{"id":595,"value":"## Earthquake Map","pinned":false,"hidden":false,"mode":"md"},{"id":637,"value":"This map focuses on the southern coast of the Reykjanes peninsula, and the town of Grindavík. *Press play* to view the earthquake formation develop over time.\n\nYou will see a Southwest-Northeast axis develop. This matches the suspected location of a magma tunnel, and the most likely location of any eruption. \n\n*Blue circles represent deeper earthquakes, red shallower. Circle size corresponds to magnitude.*","pinned":false,"hidden":false,"mode":"md"},{"id":148,"value":"viewof scrubTime1 = Scrubber(timeIntervals, {\n // delay: 0.5,\n format: (d) => new Date(d),\n loop: false,\n autoplay: false\n})","pinned":false,"hidden":false,"mode":"ojs"},{"id":70,"value":"viewof map = {\n const container = html`

`;\n const map = L.map(container).setView([63.86, -22.42], 11);\n L.tileLayer(\"https://{s}.tile.openstreetmap.org/{z}/{x}/{y}.png\", {\n attribution:\n \"© OpenStreetMap contributors\"\n }).addTo(map);\n container.value = map;\n yield container;\n}","pinned":false,"hidden":false,"mode":"ojs"},{"id":950,"value":"## Peaking into the crust\n\nThe data also contains the depth of the earthquake epicenter. This allows us to turn our map on its side, and take a cross-section of the earth's crust. By default the cross section is set at a 57 degree angle past due north, aligning it with the axis of activity.\n\n*Press play*, and watch as:\n1. The earthquakes start concentrated in one location\n2. Tremors expand outwards in all directions\n3. A second cluster of earthquakes form southwest of the first\n4. Activity continues between these two clusters\n\nThese earthquakes tell the story of the movement of magma, from initial intrusion to an established magma tube along the axis.\n\nNow, *change the angle* to visualize a 3-dimensional model of the magma.","pinned":false,"hidden":false,"mode":"md"},{"id":908,"value":"viewof scrubTime2 = Scrubber(\n d3.range(\n ...d3.extent(localizedData, (d) => d.datetime),\n isMobile ? timeIntervalMS * 2 : timeIntervalMS / 2\n ),\n {\n delay: 15,\n format: (d) => new Date(d),\n loop: false,\n autoplay: false\n }\n)","pinned":false,"hidden":false,"mode":"ojs"},{"id":540,"value":"viewof angle = Inputs.range([0, 360], { label: \"Angle\", step: 1, value: 57 })","pinned":false,"hidden":false,"mode":"ojs"},{"id":65,"value":"$31","pinned":false,"hidden":false,"mode":"ojs"},{"id":999,"value":"As of publishing, it remains to be seen when and where this magma will reach the surface. Visual models such as these allow geologists to track the magma, and citizens to prepare for it, before it even breaks through.\n\n---\n\n---","pinned":false,"hidden":false,"mode":"md"},{"id":996,"value":"## Appendix I - Other Interactives","pinned":false,"hidden":false,"mode":"md"},{"id":1027,"value":"Interactive chart for localized data","pinned":false,"hidden":false,"mode":"md"},{"id":30,"value":"Plot.plot({\n color: {\n legend: true\n },\n marks: [\n Plot.auto(localizedData, {x: \"lon\", y: \"lat\", color: \"datetime\"})\n ]\n})","pinned":true,"hidden":false,"mode":"ojs"},{"id":1031,"value":"Interactive chart for nationwide data","pinned":false,"hidden":false,"mode":"md"},{"id":1034,"value":"Plot.plot({\n marks: [\n Plot.auto(cleanData, {x: \"datetime\", y: {value: \"magnitude\", reduce: \"mean\"}})\n ]\n})","pinned":true,"hidden":false,"mode":"ojs"},{"id":1036,"value":"## Appendix II - Code","pinned":false,"hidden":false,"mode":"md"},{"id":1085,"value":"### Depth viz","pinned":false,"hidden":false,"mode":"md"},{"id":919,"value":"directionLabelMap = (angle) => {\n const label = (a, b) =>\n `← ${a} ${b} →`;\n if (angle < 0 + 45 / 2) {\n return label(\"SOUTH\", \"NORTH\");\n }\n if (angle < 0 + (45 / 2) * 3) {\n return label(\"SOUTHWEST\", \"NORTHEAST\");\n }\n if (angle < 90 + 45 / 2) {\n return label(\"WEST\", \"EAST\");\n }\n if (angle < 90 + (45 / 2) * 3) {\n return label(\"NORTHWEST\", \"SOUTHEAST\");\n }\n if (angle < 180 + 45 / 2) {\n return label(\"NORTH\", \"SOUTH\");\n }\n if (angle < 180 + (45 / 2) * 3) {\n return label(\"NORTHEAST\", \"SOUTHWEST\");\n }\n if (angle < 270 + 45 / 2) {\n return label(\"EAST\", \"WEST\");\n }\n if (angle < 270 + (45 / 2) * 3) {\n return label(\"SOUTHEAST\", \"NORTHWEST\");\n }\n return label(\"SOUTH\", \"NORTH\");\n}","pinned":true,"hidden":false,"mode":"ojs"},{"id":522,"value":"function projectOntoAxis(latitude, longitude) {\n // Convert the angle to radians\n const angleRadians = (angle * Math.PI) / 180;\n\n // Calculate the slope of the line\n const slope = Math.tan(angleRadians);\n\n // Assuming the line passes through the origin (0,0),\n // calculate the x-coordinate of the projection point\n const xProjection = (latitude + slope * longitude) / (1 + slope * slope);\n\n // Calculate the y-coordinate of the projection point\n const yProjection = slope * xProjection;\n\n // Calculate the value along the axis (distance from the origin)\n const valueAlongAxis = Math.sqrt(\n xProjection * xProjection + yProjection * yProjection\n );\n\n return valueAlongAxis;\n}","pinned":true,"hidden":false,"mode":"ojs"},{"id":1089,"value":"### Map viz","pinned":false,"hidden":false,"mode":"md"},{"id":824,"value":"update = {\n const oldKeys = this || new Set();\n const newKeys = new Set(\n [...timeGeoJSONLayer.keys()].filter((k) => k < scrubTime1)\n );\n let leaving = [...oldKeys].filter((x) => !newKeys.has(x));\n let entering = [...newKeys].filter((x) => !oldKeys.has(x));\n leaving.forEach((k) =>\n timeGeoJSONLayer.get(k).setStyle({ opacity: 0, fillOpacity: 0 })\n );\n entering.forEach((k) =>\n timeGeoJSONLayer.get(k).setStyle({ opacity: 1, fillOpacity: 0.2 })\n );\n return newKeys;\n}","pinned":true,"hidden":false,"mode":"ojs"},{"id":761,"value":"initialize = {\n [...timeGeoJSONLayer.entries()].forEach(([k, v]) =>\n v.addTo(map).setStyle({ opacity: 0, fillOpacity: 0 })\n );\n}","pinned":true,"hidden":false,"mode":"ojs"},{"id":439,"value":"timeGeoJSONLayer = new Map(\n [...timeGeoJSONData].map(([k, v]) => [\n k,\n L.geoJSON(\n d3.sort(v, (d) => d.magnitude),\n {\n pointToLayer: (feature, latlng) =>\n L.circleMarker(latlng, {\n // fill: false,\n radius: eqRadius(feature.magnitude),\n weight: 0.5,\n color: depthScale(feature.depth)\n }).bindPopup(\n `Time: ${feature.datetime.toISOString()}\n
\n Magnitude: ${feature.magnitude}\n
\n Depth: ${feature.depth}`\n )\n }\n )\n ])\n)","pinned":true,"hidden":false,"mode":"ojs"},{"id":290,"value":"depthScale = d3.scaleSequentialSymlog(\n [\n d3.quantile(cleanData, 0.25, (d) => d.depth),\n d3.quantile(cleanData, 0.75, (d) => d.depth)\n ],\n d3.interpolateRdYlBu\n)","pinned":true,"hidden":false,"mode":"ojs"},{"id":206,"value":"eqRadius = (magnitude) => {\n return Math.sqrt(2 ** (1.5 * magnitude));\n}","pinned":true,"hidden":false,"mode":"ojs"},{"id":419,"value":"timeGeoJSONData = new Map(\n [...timeData].map(([k, v]) => [\n k,\n v.map((d) => ({\n type: \"Point\",\n coordinates: [d.lon, d.lat],\n ...d\n }))\n ])\n)","pinned":true,"hidden":false,"mode":"ojs"},{"id":412,"value":"timeData = new Map(\n timeIntervals.map((d) => [\n d,\n cleanData.filter((t) => t.datetime < d && t.datetime > d - timeIntervalMS)\n ])\n)","pinned":true,"hidden":false,"mode":"ojs"},{"id":410,"value":"timeIntervals = d3.range(timeExtent[0], timeExtent[1], timeIntervalMS)","pinned":true,"hidden":false,"mode":"ojs"},{"id":163,"value":"timeExtent = d3.extent(cleanData, (d) => d.datetime)","pinned":true,"hidden":false,"mode":"ojs"},{"id":458,"value":"timeIntervalMS = 1000 * 60 * 6","pinned":true,"hidden":false,"mode":"ojs"},{"id":1111,"value":"smallScreen = width < 800","pinned":true,"hidden":false,"mode":"ojs"},{"id":1117,"value":"width","pinned":true,"hidden":false,"mode":"ojs"},{"id":393,"value":"### Data Cleaning","pinned":false,"hidden":false,"mode":"md"},{"id":525,"value":"localizedData = cleanData","pinned":true,"hidden":false,"mode":"ojs"},{"id":14,"value":"cleanData = data","pinned":true,"hidden":false,"mode":"ojs"},{"id":1091,"value":"data = await FileAttachment(\"Icelandic Earthquakes.csv\").csv({typed: \"auto\"})","pinned":true,"hidden":false,"mode":"ojs"},{"id":395,"value":"### Imports","pinned":false,"hidden":false,"mode":"md"},{"id":1172,"value":"import { isMobile } from \"@flimsyhat/mobile-device-check\"","pinned":true,"hidden":false,"mode":"ojs"},{"id":144,"value":"import { Scrubber } from \"@mbostock/scrubber\"","pinned":true,"hidden":false,"mode":"ojs"},{"id":1103,"value":"import { footer } from \"@rlesser/footer\"","pinned":true,"hidden":false,"mode":"ojs"},{"id":1105,"value":"footer(\"exploring-icelandic-earthquakes\")","pinned":false,"hidden":false,"mode":"ojs"}],"files":"$W32","stdlib":"1","titling":"auto"}